The ridiculous thing seems to be that Marvel and Disney apparently knew about all this stuff years ago as it surfaced before he directed Guardians 1, he apologised then as well and they didn't seem to care then. The difference this time seems to be that a right wing blogger and his followers kicked up a stink about it all.
While I think the tweets are fucking stupid I do think its bad that there rarely seems to be an opportunity for people to have believed to have grown or changed in the years since. If the tweets were new then it would be different but the guy apologised and completely owned up to them.