Unfortunately DK isn't a horrible character by any stretch of the imagination, which is really just the first flaw in your argument. G&W has insanely powerful smashes even if they're hard to land, and he's pretty high up there. D3 is one of the heaviest characters in the game and he does incredibly well because of his range (including grab and a CG on like 2/3s of the cast)--which you totally disregarded in your analysis, and which plays at least a big a part in Snake's tournament placement as his power. Samus has lagless aerials, Z-air, many options, and tons of ways to attack people, and she's pretty terrible, because she's not powerful enough to actually kill. Pit can get tons of virtually free hits on people and he isn't doing nearly as well at tournies as he used to, for a variety of reasons. I really don't think putting so much emphasis on payoff / ability to hit people alone is going to get you anywhere.
If you look at the post carefully, i was trying to avoid absolutes. My point was not that Dedede is a bad character, or even the Dedede's Fsmash is bad. My points was that over time, at different levels of ability, the payoff will remain the same.
However, over time, it will get avoided more and more because it is slow/has bad usability.
Therefore, over time, that move will become less good.
Less, not totally worthless, less.
There are many other attributes besides payoff and usability. I didn't mean to ignore them, i was focusing on one attribute of characters that i believe changes over time.
If you recognize the narrower claims I'm making, the fact that DK is a (really) great character is not a refutation. For one, he has moves with very good usability, his ftilt is fast and ranged (usability as i'm using the word includes range), his moves has super armor which helps them land, and his bair is very fast and ranged.
I don't even claim that the DK's Fsmash will eventually fall behind Sonic. DK has more payoff than Sonic. That payoff will become less important, and could possibly close the gap between Sonic and DK, but will probably never lead to Sonic being a superior character. (also, you could make a strong argument that DK can land hits more consistently, he has great usability. I didn't even get to mentioning the great range on his grabs).
Your mention of G&W's smashes goes back to a concession that i make: the payoff on G&W's smashes will become less important as players get better, but players will never get so good that G&W's smashes are no longer making him a good character. Maybe he could shift behind a character that is already good, like Falco, but his payoff will always remain important.
