The Tier system is not saying that T1 classes are the best classes to play. The Tier system is not saying that the DM has to let T1 classes wreck the game. The Tier system, when it comes right down to it, is a measure of two things: how much DM intervention is needed to make the game work for certain classes, and how much power lies in PC hands when playing certain classes.
T3 classes are generally the most balanced classes, and can handle CR-appropriate encounters fine without much buffing or nerfing of either the PCs or the opposition. T3 PCs can influence the game world to a good extent but usually can't completely change the world or circumvent every challenge.
T1 classes are generally more powerful and versatile than everyone else, and can overpower CR-appropriate encounters to the point that the DM needs to either present them with above-CR encounters on a regular basis or optimize CR-appropriate encounters with good tactics to keep up. T1 PCs can influence the game world on a massive scale and can completely dominate everything from kingdoms to dungeon crawls if they aren't checked.
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The variation in tier isn't a development failure in and of itself; the development failure is WotC assuming that they could remove most of the caster restrictions and non-caster benefits from AD&D and retain the possibility of having casters and noncasters be on a roughly even playing field in the same party. T1 characters don't wreck the game inherently if the DM knows what he's doing; I've run games with 5-6 T1 casters in the party and it's worked out fine because I was able to provide them a challenge with intelligent T1 opponents. T5 characters don't fail at life inherently if the DM is willing to work with them a lot; I've run games with 5-6 T5 noncasters in the party and it's worked out fine because the players knew their classes' weaknesses and played to their strengths in a campaign and campaign setting built with an eye to T5 limitations
The problem comes in when you try to have T1 and T5 characters in the same party and the DM doesn't compensate for this. You're saying "Well, the DM can always..." and the response is that yes, that's exactly what the Tier system is for, to tell the DM that he'll need to adjust things up for T1s and adjust things down for T5 and put in significant effort to challenge a party of mixed tiers, unless the players are aware of the problems with that setup and can hold back/self-nerf/compensate the lower-tier PCs/otherwise equalize the PCs via gentlemen's agreements. Rather than being the ultimate expression of nerd superiority, in many games T1 casters (and sometimes their T2 brethren) are nerfed or banned altogether. Quite often, T5 (and sometimes T4) classes are also banned because there exists no quick fix that will let them "play with the big kids," or they're buffed far past the extent of a quick fix, or the underlying system is changed to let them compete through a combination of caster nerfs and martial buffs.
Not quite.
Look, I can't speak to anyone's individual experiences. If you say you tried to run a campaign with Wizards and Fighters and it didn't work...so be it. Nonsi256 just gave us anecodote of his Tier 3 Beguiler being so dominant over a Tier 1 Cleric, he got kicked out of the group. We have no way of knowing that the skill level or effort is of the various participents given the classes. And there in lies the first and ultimate problem with the Tier System: are the assumptions valid?
In any analysis, the analyzer makes assumptions. The validity of the analysis is based on applicability/accuracy of the assumptions made. Let me ask a couple of questions that speak to this:
1) Do D&D campaigns really work they way JaronK assumes in his examples?
2) Are his methods of comparison internally consistent?
3) Does he shift the goalposts? Does he talk about camparing A...but then really compare B?
There are a truck load of problems with many of the assumptions made in the Tier System ranking. Perhaps the biggest is the conflation of a "optimized" build with the notion that you can optimize to outperform all classes simultaenously (which isn't optimizing), and that you can maintain that level of robustness (which outpeforms every other lower Tier class) throughout an entire campaign.
A big problem, imo, is how JaronK approaches Wizards. The Wizard or Cleric, in the context of an actual game...cannot bring the full power of every knowable spell to every encounter. Jaronk ignores this because he talks about
potential. But that
potential is meaningless if it is illusory. The player character does not know how many times he'll need Fireball versus Haste versus Water Breathing and it's not like he can cast ten of each at 10th level.
Yes, a Wizard can go home and study Rock to Mud and bring down a castle wall. Gee, do you think the guy who built the castle wall never contemplated such a contigency? Do you think the guy who kindnaps the King's daughter never considered what a 10th level Wizard might do to find him? Jaronk acts like the world of D&D never met a 15th level Spellcaster with Genesis or Contact Other Plane before.
The perception of balance is contextual. Tier system tries to present perceived balance as an absolute. He claims one of his goals is to prevent pre-emptive nerfing of Classes...and yet he's advocating the exact same thing. He's trying to convince you that you need to nerf Tier 1's to play with Tier 5's or you'll be in over your head as a DM. Nonsense. If you don't know what you're doing as a DM...you're going to be in over your head no matter what classes you have. You may think you're going to "balance" the game by having a mage battle...only to find the Monk with Improved Grapple and 8 ranks in Tumble and the Run feat has moved 5 times his move rate in one round, grappled your caster, and pretty much ended the threat in two rounds.
Any class can derail an encounter if you don't consider the full range of that class' abilities. The fact is that most DM's are less familiar with designing encounters to contend with powerful casters because most DM's have less experience with it period. We've all DM'd Fighers and Barbarians. We've all DM'd people who love to play martial classes. A much smaller subest of people like playing spell casters (statment made by Monte Cook and impetus for why they improved spell casters in 3e to begin with). As a result, DM's have less experience with the available spells and the consequences of those spells. The world of D&D has dealt with spell casters for over 1000 years even if you, as a DM, haven't.
What Jaronk and I 100% agree on is that if you grant any Class unfettered access to Spells, you're going to have a harder time managing the game. It doesn't matter if access to those spells is through a Class ability, items, or cohorts/companions. That doesn't mean Classes who can access Spells are broken. Manage the Spells and you fix all the Classes that have access to those Spells.
JaronK and I also 100% agree that just because WotC wrote it down, doesn't mean it belongs in the game. Monte Cook, a game designer for 3e, has publically stated that WotC screwd up with the Harm spell. There's no rule that you have to allow splat books.
Kahn_bloodbane is correct. Balance has no meaning in an RPG. The game cannot be balanced because you are comparing things which have contextual purpose/effectiveness. You can't balance context. You can't "balance" the Track Feat with the Extend Spell Feat, there is no scientific way to do it. The best you can do is create some perception of fairness...and fairness isn't balance. Fairness is subjectve.
The bottom line is the Tier System is a product of the underlying assumptions. Every DM is capable of deciding how well those assumptions describe the conditions under which the players play. It's self evident that if you give any Class unrestricted access to ALL resources be they spells, contacts, magic items, Feats, or Actions, you're going to have to prepare for more contingencies in a campaign. That does not mean a Wizard and Figher can't play in the same campaign without the DM bending space and time to make it happen. Stating or presenting such is just irresponsible posting.