@frankiesaxx 
Short not too detailed history (I know a decent amount for a quick rundown in chronological order)

Mastodon launches, federates okay.

Gargon, guy who runs it, asks a bunch of devs for help.

Gargon starts being a lot more rude and insulting to people trying to help, or people just with different political opinions, his userbase at the time does too. This coincides, to no surprise, with them requesting cutting off federation. 

GNUsocial people ain't happy, a lot of the users that were being witchhunted are the far more peaceful ones, they voice their complaints, try to help eachother out a bit more, their bonds are strengthened through a common "wow a bunch of those Masto lot are dickheads huh?"

Main-Masto starts cutting off federation more and more, handing out bans, Gargon continues being a prick.

Masto gets more popular, new people have no idea of Masto being shit in the past, assume "GNUpeople" are bad guys.