Balance matters most to those players. The more casual you are, the less balance changes effect you, and the less all of this matters. And you don't need to be THAT high level of a player...
Check out a quick line of logic real fast.
Captain Falcon's Forward Air when shuffled does an enormous amount of damage and knockback, and can be used rapidly. Ideally, you want to hit as many knees as possible, because of the current balance of the game. When a combo would do more damage, or they are not in an area you can hit the knee, or if they are defending from the knee, you need to do different things. This leads to all of the tactics related to Falcon, but ultimately you want as many knees as possible, because it's his best move. Most characters have a movie like this. The strategy in a way revolves around it.
However, when you change a move like that that is CENTRIC to how the character plays, you change the entire way they play. Let's say now knee is less powerful than down.air. This changes EVERYTHING about how falcon plays, with seemingly 'minor' changes to the balance.
Jenga. You don't patch fighting games.
Ahhhiee dunno. Even though a casual player might not be able to really tell that character A is broken because some of his moves have no lag and too much power, they will be able to tell that they keep losing to their friend who plays as character A, and that they keep jamming on the same moves over and over again. It's that kind of stuff that can make a game no fun for, say, a 12 year old just sitting down to play at a birthday party.
That's one of the reasons some games were never any fun when we were kids. You pick up the controller, and someone's already figured out what's 'broken' by finding what works a lot more than it should, and they just take the match out of your hands.
It also seems to me that, say, playing Falcon, you'd have a number of varied combos at your disposable, but frequent the ones with the highest output. You'd have the character pretty well known, both what he's good at and not, so if the knee gets nerfed, you just do some testing and find out what the next best thing in, slide your knee dependent setups a little lower in the queue. It's still Falcon, but you have to take everything you know and shuffle it around a bit. If you focused all of your energies in a match into getting things into a point where you can do that one strongest move, well... I dunno what to say about that.
It might seem mid/low leveled of me, but I usually think of characters as army knives, all with different tools for encountering a situation. If all of a sudden, your fork gets unreliable, well, you might have to learn to eat with your corkscrew or knives now and then.
I do maintain that when things are REALLY unbalanced, casual players can tell. (So many fighting games have 'that one character' or 'that one move.' I swear to god I could beat anyone in MK back in the day with lots of time and a thousand jump kicks.) And when it's like that, a patch can be a big boon for fun factor and sales. I don't want to see the tournament scene riddled and upset by constant updates, of course. I just think for the benefit of all the players, some annoying re-learning might be worth the trouble.
(I also wouldn't say that if I didn't think Smash has as big of a casual base market as I think it does. While Smash might have one of the largest, if not the largest, pro scenes, the majority of players are still casual via percent, which is a really big difference from Guilty Gear or even Street Fighter, where a good majority of the people who buy the games are going to get pretty deep into their environments. I'd definitely say no patches if this were a game like that.
Also, unlike Guilty Gear's every-other-year iterations, it seems Smashes are coming really fa r apart. If things are broken and can't be patched, we'll be spending another, what, 4+, maybe 6 years just dealing with it.)
...Banana peel!?