Woah, didn't except to see myself quoted outside of that thread!
What can I say though, I generally at least start, if not stick with, the grappler or some heavy in games I play. Zangief, T Hawk, Hugo, Alex, Iron Tager, Kanji... I could go on. Its not even like the vast majority of them have their own set of problems, its ALWAYS is the same, due to this design decision that the slow is always an extreme representation of his issues.
Hugo is a GREAT example right now in SF4. The reason? He is pretty much the greatest "grappler" in fighting games right now... if not history. Note why I used grappler in quotation marks. Because I mean just that. He does everything in as "grappler" a fashion as you can do. Heck, even a couple of jabs from him can break over 100 damage in a game where he and the other grapplers set the bar at 1100 health. He has stupid damage and scares you to bejeebus if he gets close... IF HE GETS CLOSE LOLOLOLOL. Dude is zonebait for days, as even crouching he can be vulnerable to projectiles. Sagat in particular eats him alive. And as it turns out, he actually has so much slow movement he isn't guaranteed anything up close, although he has respectable fear factor there.
The worst part, of course, is that it is not like his damage is all that mighty when compared to the other top tiers. And that may be part of the problem, the innate factor of balancing that someone is going to have some good safe damage that makes even that promise from the big guy seem sad.
The giant problem with grapplers is that they are the definition of noob-stomper. Seriously, learning to beat a grappler is a good goalpost for when you move on from complete newbie to someone on the way to learning fighting games. How to perform SAFE offense, how to play neutral, how to punish, how to NOT get punished, NOT SPAMMING. Above all else, how to be patient. And so most developers fear making them "good" because who knows how much their newb-stompiness would get then. But the thing is, it might not get THAT good.
A great example is Iron Tager. He is an amazing skill gate character because of command grab, a super reversal AND super command grab that can ghetto reversal, an armored move and his own version of the Banishing Flat that is frankly crap against -good- zoning, but can punish spamming in a pinch. The REAL newb-stomper, though, is his Gadget Finger, where he picks up a sod from a knockdown and sets them standing... with him at +3. Now, this creates a mindgame that has all sorts of variables at higher level play, but at its most simple with tools everyone has, he basically can jab, backdash, or grab out of this. His jab can be blocked, but otherwise beats out attempts to mash through him and attempts to jump or dash his grab. His grab beats the block. And backdash is invincible, so it becomes a factor if the opponent somehow has an actual answer to him at +3 and them just standing there (SRK, another Tager with grab.) Now imagine a newbish player, who may know how to block and likely is a little overzealous in attacking back. He won't know how to answer the Gadget Finger trap at all. He'll probably try some bigger move that gets both jabbed and grabbed cleanly and thus open himself up to the scariest thing you could think of: A grappler with a vortex. Its not real, but the lowest level of play will make it real.
Now understanding HOW he beats newbies is important in context of what he needs buffed. He has little gauranteed damage. Ironic right? But for the past couple of iterations, alot of damage is hard to acquire, or involves risks or gimmicks. I believe the newest one out right now gave him a safe route of off jab, which was big, but it is still not enough. He is STILL too slow, his hitbox allows for special combos, and he gets zoned for days. Better normals, superior zoning answers... Notice none of those make the above gadget finger stomp vortex any better. Its just the archetype happens to carry tools that will kill a newer player, but making other aspects stronger, the ones that NEED it, won't really make it -worse-.
So, err... yeah. Sorry for the dissertation. As you can see, I have thoughts about bigger characters. They are nice BECAUSE they can have a lower combo count and are slower. They reward me for doing more thinking and careful decision planning, because sometimes I suck at the speed other characters ask for. But when the heavy is too slow, too reliant on reads, mistakes, and gimmicks, like is this epidemic we have, then something has got to give...