Why can you edit players in association mode?

Because you can. It's not odd. If you don't want to edit it then don't go to the player edit screen. It's a good thing the devs gave the gamers an option to somewhat correct and edit mistakes in player details/ratings that they might have overlooked. Just because it's there doesn't mean you have to tinker with it.

That's why if I will go to edit player I will not stay long in the "rating part" of the player because for sure I will be tempted to edit those and it will be so unrealistic for me.

Plus it allows you to update players according to their performance in the current season. e.g. Rose has improved his 3 point shot tremendously and thus his 3pt rating can be adjusted to match.

Yeah theres nothing wrong with it, if u abuse it then your just cheating yourself. Its there for good reason, not for you to up all your players to rating 99.

I was surprised too, and tempted to cheat the association. But I know it's unrealistic.

I use it for accesories

i personally use it for a lot of stuff.. first and most important, some players stay very good even when they're old and i adjust that, it's a personal taste.. another thing i do is use it as sort of a my player, i put my created player into my team (knicks usually), then i create a story in my head like he becomes very good in a few years etc lol.. and also right now i use it for ricky rubio, i created a ricky rubio and edited his stats so he's like a 50-60 range so no one will take him in free agency, but he doesnt suck so much that he'll disappear after the season is over.. then come 2012, i'll edit him to his normal rating (i have him at around 76) and hopefully a team grabs him in free agency then.

^I'm doing that when I'm bored.