it breaks the social contract of tolerance and seeks to end discourse by killing the participants when escalated to its final form. hate groups are no more participants in discourse than fire is an architectural style for building a house.
we don't have to take seriously the folks that suggest "let's set it on fire" when discussing whether we want to build a victorian or modern style home because they are not serious people and their poor ideas have been proven idiotic too many times to count.
how many years of lost productivity and set backs in open web standards because of their internet explorer nonsense and you're saying it wasn't a successful execution of this strategy? i think they won and set back the open web by years.
one point about the mit license is that it's not copyleft because mit license does not protect derivative works. that is why they fought so hard against gpl licensed works and even forbade the gpl3 license on codeplex. mit license is no threat because it can be incorporated into closed source products.
with github, i don't think they are going to pull a musk or a spez, they are going to wield their influence carefully to frame the conversation and tools around open software to work in their favor as they have always tried to do. i do agree that they seem less outwardly aggressive than back in the day, though.
as far as facebook in the fediverse, they will have the ability to inflict significant, if not fatal, damage, just like ms did to open web with ie and just like google did with xmpp with gchat. that's something worth discussing.