> I'm saying anyone can write their own client but the burden is on them to drum up support and achieve consensus if it's going to be useful.

Consensus aside, this is a lot harder said than done. one of the reasons btcd is not widely adopted, even though it's purporting to be 100% compliant with core, is that there is no formal definition of what that even means. to be 100% compatible with the bitcoin protocol is to be 100% compatible with core - bugs and all. the community needs an RFC like paper describing in details what 100% compatible means. Then we can safely run other nodes without worrying that we'll get screwed by not having the same bug as core for example.

I'm not one to believe in conspiracies or even subscribe to the thinking of core==blockstream. But I don't think you'll disagree that what goes into the consensus protocol is under control of the 5 maintainers