Not trying to start a Brawl vs. Melee debate, so don't take it that far, please, but afaik, Melee had its fair share of dumb combos as well. That's just how a game like Smash works..... Brawl's gimmicky mechanics happen to make it look worse because instead of a "legit" move, it works out of something like a footstool.
I'm not trying to start a Melee/Brawl debate either, but here are my two cents on Brawl's discoveries with these new combos/chaingrabs/etc.
Most of Melee's combos involved the person being comboed to have some control over their character; usually this is DIing in a direction and teching into a platform to try and trick the opponent and escape the combo.
In other words, you have interactivity in the game. People like games that are interactive; it's simply natural because both people are having fun.
A lot of the stuff that has been discovered in Brawl like DDD's true infinite on DK, ICs infinite throws, and footstool combos are for the most part
non-interactive, which means the victim has little or no control over what their opponent does.
These types of non-interactive combos instill a sense of complete hopelessness in the victim knowing they can never get out and have no options of escape. This is also why Wobbling in Melee was (and still is by many people) shunned by the community when it came out because it is a non-interactive infinite. Even though Wobbling has shown it didn't break Melee and it didn't make ICs god tier, people still banned Wobbling simply because of its non-interactivity.
Disclaimer: I am against banning DDD's infinites, ICs, infinites, footstool infinites, or infinites and/or chaingrabs of any kind unless they have proven they degenerate, overcentralize, and break the game.