I can see how some people, especially fans of 4e, would be somewhat disappointed with the current iteration of the playtest rules. However, for me and many people D&D is a role-playing game rather than a tactical miniatures game.
Implying that 4E fans want a "tactical miniatures game" and are not really interested in a "roleplaying" game is not going to help this discussion at all.
Regardless, you're wrong. 4E is an RPG, and 4E fans want an RPG. Anything else is just you deluding yourself or trying to dismiss the tastes, desires, and needs of others. You don't have to like 4E, but it would help avoid some of ENWorld's eternal edition warring if people like you at least gave other people some amount of respect and didn't try to imply that they are not real D&D fans.
Although most adventures will involve combat, tactics and strategy are not as important as telling an exciting story. I like the idea of quick combats that can be resolved without the use of miniatures and battle grids. (What the 5e design team is calling "theater of the mind".)
Also, on the issue of balance, I have come to the conclusion that complete balance in all areas of the game is an untenable holy grail. Should "balance" even be that important? The idea that every class has to be the absolute best at one area strikes me as somewhat of an artificial "meta-game" idea. I don't mind classes being inherently unbalanced as long as all of them have some role to play.
I think you don't understand either the extent of pre-4E imbalance, or the real idea of what balance means.
Complete and perfect balance is indeed an untenable holy grail. That said, it is still a goal worth pursuing, and it is simply unacceptable to tolerate gross imbalance simply because perfect balance is nearly impossible to achieve. And really, 3E has gross, disgusting, and entirely intolerable levels of imbalance. In other games, most of the discussion of balance really only concerns the 5-10% difference between options that only matters in highly competitive or high-skill play. It concerns things like correcting the trivial advantage given to the layer who moves first in Go, which is meaningless to low-level players but statistically meaningful for professionals (to this day pro Go organizations work to correct this imblance).
3E is not that level of imbalance. It is more like a 500% difference between options, which has a dramatic and unquestionable impact on players of any skill level. The higher the skill level, the greater the negative impact. I can say without any exaggeration or hyperbole that 3E is one of the most imbalanced games I have seen, and might very well rank high on the list of the most imbalanced products to have ever been created. So, yes, perfect balance is impossible, but 3E D&D (and 5E as well, from what has been shown so far) is so far away from being balanced that worrying about the impossibility of perfect balance is utterly meaningless.
Also, giving each character a role to play is an important part of balance, and is an important part of why many versions of D&D are imbalanced. You see, one of the biggest problems people have with 3E is that the Fighter simply
doesn't have a role. There literally isn't a single place in the game where you want to have a fighter in 3E. Almost everything the Fighter can do the Barbarian can do better. The Druid's animal companion is more useful than the Fighter in almost every regard, actually. Casters like the Wizard, Cleric, and Druid make every other character type almost completely redundant and meaningless as far as every single game mechanic is concerned, both in combat and even more so outside of it.
So yes, giving each character a role that makes they can play, even if they are not strictly the best at that role, is good. What isn't good is telling the player something like "the Fighter is the best at fighting!" and having that be a complete and utter lie (or maybe just complete and irredeemable incompetence on the designer's part). Because, you know what? The Fighter is not the best at fighting. He's pretty much the worst at fighting, actually. And I don't think it is acceptable for a product I've spent money on to lie to me.
As far as the OP's contention that the fighter is not that powerful compared to other classes such as the cleric, I would caution saying that we have only seen an early draft of the playtest rules. From what we have heard there will probably be some more maneuvers presented in the next iteration. It is very likely that the fighter will get some bonuses to the said maneuvers. Also, one must remember that the spells are a limited resource. Sure Crusader's Strike will give you an extra 1d6 damage, but it only last for an hour and most adventures I've played in have more than one combat per game day.
You know, this has been said before, but just because it's a playtest doesn't mean we can't comment on the imbalance. Playtests only function properly if people do give feedback, and lots of it. What's more, we have no incentive whatsoever to trust WotC to fix this. We gain nothing by trusting them (particularly since they have done a lot to erode that trust), and we have a lot to gain by voicing our own feelings (even if the hope for that gain was misplaced, at least we made the effort).
Also, just because spells are limited resources does not make them balanced. 3E proved that. Balance would only be created if that limit is carefully studied and thoroughly playtested. It will only ever be balanced if the people in the playtest speak up about whether it works or not, and the people at WotC make fine adjustments. Telling people to just trust them is actually just going to sabotage any attempt to create any balance at all. Balance isn't magic; it's a process of experimentation and mathematical analysis based on data. Trusting that a simple limitation will balance something powerful, or that someone can just "fix" it, isn't even the right approach to balancing something.