I generally dislike bming, but eg's "trashtalk" isn't exactly malicious to any degree. Boostio and Demon1, the two most prolific offenders, have both made efforts to not single any team out and to maintain friendly relationships with the other team, regardless of any narratives set. EG and EDG literally hung out before the match and KangKang was trash talking back; it's a two way street of trash talk and it's perfectly fine. Trash talk the way EG are doing it makes the games that much more entertaining, and if they can't back it up, it's all the more better because you know every single person would absolutely shit on EG if they lose that game. To address Gais, he had a mental break because he knew they needed that first map, and PRX are generally a demoralizing team to get crushed by -- your opponents hopping around yo is disheartening to see.
For Boostio's comments about KangKang, he really didn't have a star performance yesterday like everyone would like to see, so calling him disappointing is justified in the context of his performance. Tbh, I don't really view it that differently than a caster calling out a player for a weak play or a dumb peek.
TLDR: BM in EG's context is fine and people are taking it way too fucking seriously. If you really dislike it, root for drx or prx/loud to fuck them in an official match. Until the time comes when the line is crossed, and you'll know when the line is crossed, ignore EG's banter if it really means that much to you.