This seems like a good time to point out that most changes in every patch have been buffs. People always overreact to nerfs, but for any patch where one character got nerfed probably three others got just as large of changes as buffs.
I'm really in favor of balance patching; not balance patching has predictable and detrimental outcomes. In Melee, it resulted in the bottom half of the cast being completely irrelevant for basically the game's entire lifespan. In Brawl, lots of serious problems (like ICs chaingrabs) just festered, and MK really needed nerfed but never was (unless you played Balanced Brawl, great project that one). Sheik, Rosalina, and Diddy in their original (1.0.0) versions were all probably good enough to seriously damage the game long term; look at how much damage Diddy did since they waited too long to nerf him, and then realize that 1.0.0 Sheik and Rosa were a lot better. All of Olimar, Shulk, Ike, Falco, and Charizard at least (arguably more characters, Kirby and MK definitely on the table) got buffs large enough to significantly change their playability for the better. Abusive gimmicks like G&W + Pika doubles bucket, Olimar pikmin amplification, and Villager under the stage stall have been fixed up. They even fixed that small bug on Wuhu Island and significantly improved Lylat Cruise. Obviously we still don't know everything about the long term balance of this game, but on the surface every patch has made the game as a whole better. Even as a Rosa main, I'll happily give up the easy wins with my previously overpowered character in exchange for playing a better game that will have a longer and healthier life.