hayesthe reason why that situation was especially divisive was because 1.) The entire bitcoin mining scandal at ESEA creating distrust between the playerbase and 2.) you had to play ~ four matches a week on CEVO, meaning it was virtually impossible to play both leagues at once.
Point 1 was true, but point 2 is technically wrong, it was the exact same as ESEA (2 matches a week, but the map rotation was not the same because esea refused to work with cevo and cevo refused to change their schedule once esea posted theirs). The issue with cevo was not the admin staff, nor the week structure, nor the client, but that the platform was not really ready to host a league for a large number of people. Forfeit rules made it so that you never had a forfeit game but that game wouldn't be played that week, instead is was pushed to the next week, creating weeks where you had more the two games. Dead teams also weren't properly dealt with which compounded the issue week after week.
However, this isn't what killed the league, what killed it is what is going to determine what league survives this uncooperative mess that these league admins are creating. The top teams didn't all switch to the league. I think there might have been one or two teams that only played in cevo, but the rest were dual league teams. There were significantly more unique esea teams than cevo teams for the first season of cevo (and beyond). With the above match scheduling problem, a worse (which I didn't know was possible at the time) to navigate website at the time, and no LAN support (until it was too late), there was really no compelling reason for those on ESEA to switch over.
As Screwb says, unless you are on an invite or playoff IM team, you really don't get a say where the bulk of teams play next season unless you can convince one of those aforementioned teams where to play. If you are an invite or playoff IM team, then the most important thing for 6s stability is that you all agree on ONE league to play in.