1st part he is a very good qb. he essentially had to audition for his job every year, the media never embraced him and thus put the seeds in the air to get him out of there even when he was healthy and make no mistake about it whenever he was healthy he performed at a high level.
2nd part people blame him for the team struggling and not the overhaul of the entire roster and coaching staffs 2 years in a row. if you and your team you manage do great and then i replace all the key parts that you managed successfully and then said hey do the same thing with these lesser parts.. and then when you didn't i blamed you and reviewed your performance, you'd say...tf? how am i supposed to produce the exact same output with lesser people to work with?
same concept.
it wasn't disagreeable to even the 49ers. he won teammate of the year voted on by the teammates in the locker room. black and white players in the actual locker room said he isn't a distraction and supported his stance.
even the ones who didn't agree with it as far as kneeling agreed with the message behind the kneeling.
so the only real distraction is the fact that they don't want someone speaking out against what he spoke out against in an unapologetic manner as he did.
everyone you mention atoned, and apologized for what they did which was wrong.
so then the question becomes how does one apologize for saying he wants everyone treated equally under the protections of the law in all facets of life?
and since they have a problem with that, how is he going to get on a team when he can't and shouldn't apologize for saying something that wasn't wrong and ideally, or as they would want you to believe, in theory want the same thing right?