There's a logical issue with the comparison to D:OS2 is though, because the characters in that game are somewhat specialized, but you can still have swiss army knife characters that are good at everything. Even if you specialize characters you have a crap load of scrolls and items that make it possible to go without spreading your points fairly easily. In D&D however those options are not as readily available, and nor should they be(even if it is a video game as the argument seems to go). In D&D people are forced into certain rolls that don't really change throughout play(Though there is some evolution), and I think the only thing that limiting the party size to four does is make the developers feel like they need to add more food and scrolls and potions to the game to make up for it. I think with a rebalance of resting and encounters (which apparently are done by an AI now) the game would be vastly improved with one or two more companions available. Then the need for items to keep yourself alive and barrels to give you the advantage(or outright cheese the system) would be somewhat mitigated.

Reality is Merely and Illusion, Albeit a very persistant one - Albert Einstein