People are equating "competitively viable" to "fun to play". You need to realize that viability isn't the whole story here.
Here's what I think: Yes, I appreciate how they gave him slightly better mobility. I appreciate how they gave his aerials better frames. This is the sort of thing you do to make a character better between games.
Ganondorf's smashes are how you don't make a character better between games. Smash attacks are a crucial move slot for all characters due to their role in being finishers. But it's not enough for the moves to be good, they need to mechanically and thematically fit within the moveset.
And this is why the sword smashes are enough to ruin playing as him for me. Yes, the range makes them better (except for usmash debatably), but they just don't fit his playstyle. Mechanically, Ganondorf is supposed to be about close, strong hits, so there's no reason for his smashes to have massive hitboxes. Thematically, Ganondorf is supposed to be about raw physical strength with no need for projectiles or weapons, so there's no need for the animations to involve a sword.
I assure you, if his Smashes had the increased power of his sword smashes, but the old animations from Smash 4 AND frames as good as the Smash 4 u-Smash, MORE people would be happy than just tacking on those sword moves. That way he would have the viability that people prioritize, and NO ONE would be unhappy about his Smashes being changed.