It's really simple. Core becomes less "core" and eventually not-Core. They took a whack at their own status. The only question is whether they will retain enough credibility for when they really try to sell out for a big prize. Let them spend down cred on this while the ecosystem adjusts to boost viable alternatives and everyone wargames how we would handle an even more contentious and dangerous change. Once they have tasted power, they will want more. Bitcoin is not centralized so there is no one to "fire" them. You just have to run different software and stop paying attention. If someone will release a v30 with the OP_RETURN configuration limits in place, it would be very popular right now.