This. So much this!!
Because this is false.
My grass is getting noticeably worse every single day, and even days and days of rain haven't helped to fix areas that I rarely even walk on to begin with. In fact, I notice them continuing to wear away even with my flowers being watered every day. I think the theory that loading your game in itself/going to black saving screens such as through wifi connections actually kill off your grass every single time by small amounts, but doing these more often obviously adds up.
People complain about it because:
1. It's a 100% useless feature in the game.
2. It's a useless feature than virtually nobody ever liked in past games yet they brought it back anyway.
3. They bring it back yet don't give us any practical ways of combating it. Honestly, grass wear wouldn't be an issue if they made Beautiful Town ordinance prevent it from happening, or drastically speed up the recovery process.
There's absolutely no reason for this feature to even exist in the game except to make your town look progressively worse... for no reason other than to just do what it's doing.