You didn't make any new points.

Yes it is the dominant implementation, and I currently like the core developers, but human nature being what it is, at some point there will be some key developer who determines who gets added and who gets kicked from the core repo who turns arrogant and ignores social consensus. Yes that is not the case now but don't miss the point.

Now, a new point. I like the idea of super soft forks. Wherein an alternative implementation soft forks, rather than merge with the majority implementation. If the soft fork has a bug that hard forks them from consensus, instead of accepting the bug as consensus, we can just fix the bug. Yes this would mean you'd be forked until the fix came in (or you imported your private keys to a working implementation in the meantime), but while it was working you had access to use a soft fork feature that the majority didn't have and the majority keeps their security in the meantime.

Being forked also doesn't mean the world ends. You just have to understand what you're getting yourself into and accept the risks with as much mitigation as you can.