I disagree. Back in the old days a party was just a collection of whatever characters the party wanted to play, and the DM tailored adventures (on the rare occasions it was necessary) so that it matched the party capabilities. It could still be a sandbox, while allowing for flexibility in how the game was played.
Itn that mode of play there was never a NEED to have specific party 'roles' covered - and was all the better for it.
You say this like it is some kind of absolute. Well it doesn't match my experience at all. My group has always made sure that the basics are covered. Back in the old days that meant having at least one cleric, one fighter-type, one wizard, and one thief before any other characters were added. Whereas now they don't always have each of the four roles covered when creating characters.
Both of these statements seem to be absolutely missing the point.
Umbran explained best why I think you're missing the point. In the 'old days' you didn't choose a Fighter if you wanted to cast spells. In 4E you choose Ranger, or Rogue, or Seeker, or Hunter, or Bard, or Warlord if you want to be the ranged weapon guy, not Fighter. The only difference is that previous systems used to let the Fighter fill this role. Things change, but the missile-weapon high-damage low-defense guy still exists, he just isn't called Fighter any more.
But this is also a mechanical effect that has in-play consequences. The holy warrior archetype has traditionally been good against evil and undead... in 4e this is partly expressed through his use of radiant damage, a barbarian doesn't get these types of powers.
If radiant damage is important to your concept, then you have to find another way to achieve your concept. But as you keep adding additional requirements to your desired concept you sound like someone wanting a Mary Sue character, IMO. Maybe someday they will develop a heavy armored radiant striker. But they'll hopefully put more thought of balance into it than just saying "take a barbarian and slap radiant on all his powers." You have the tools to make the character you want, yet you complain that you are asked to pay for those abilities or sacrifice something to achieve what you want. The balancing of a new divine striker/defender would build in those same costs or sacrifices.
Or. like I said we could not conflate an archetype like holy warrior... with how he chooses to fight in combat. And there are many games, including previous editions of D&D that allow exactly what you are claiming can't be done.
Maybe you could give me an example of one and I would better understand your argument. I feel like you and I have different defintions of Striker.
Let me flip that, what about the holy warrior or paladin archetype makes him intrinsically fight in a defender role? Why is one even connected to the other? Isn't this just as arbitrary as my concept being a striker?
Nope. I already told you it fits my understanding of the stereotypical paladin. If you want one that breaks those stereotypes then you either need to 1) use feats, multiclassing, or hybridization; 2) design it yourself; or 3) wait for someone else to design it. I understand the designers choice to stick with the most common stereotype of what a paladin is.
On another note why do I have to sacrifice the ability to have radiant damage powers in order to be a striker paladin?
You don't. You can be a hybrid and still have radiant powers. You could be an avenger and break the stereotype of holy warriors being buried under plate armor. There are alot of options open to you.
Yes, I knew you were talking about the system rules. No, there's nothing wrong with assuming anyone can homebrew, because literally anyone can, and in every system I've ever played they encouraged it in the source material.
Or so I thought, at least. I guess the reason I bring it up is because I have very little experience with 4.0 and I wanted to see if homebrewing was encouraged/doable in 4.0. I take it from your response that that's not the case?
Homebrewing is not as widespread as you think. Your personal experience has no bearing. Many DMs I've played with since the beginning of the game will not allow homebrewed material. That is why you can't assume. Even if they allow homebrewing, they may not like your current offering and reject it. That is why you cannot assume.
The one detriment to homebrewing in 4E is the Character Builder software. It currently does not allow outside material to be loaded. But if you are willing to make your character without technological help (like the good old days) then this impediment disappears.