Developers are politicians, in my opinion. Choosing to run different versions of the software is a vote. Paying transaction fees is paying taxes to the military of Bitcoin: the miners (security model). Politicians get money from lobbyists (sponsored by companies that depend on the Bitcoin ecosystem). In Bitcoin, the politicians are checked, then, by users and miners. I see criticism at a much more fundamental level, then, than on Ethereum. A "tradition of criticism" is the engine of all Western progress [of which Bitcoin is a part], and that you don't see in, say, Russia, China, North Korea etc.. IF they do go to proof-of-stake, where does accountability lie? Right now, I already feel there is no real accountability for lost funds and chain splits. Vitalik sort of disappears into the the ether (see what I did there) of his political "party," to maintain his status and his parties dominance (of which there is no competition). Where as, within Bitcoin there are REAL parties even within maximalists. Luke and Rubin have fundamentally different visions for the future of Bitcoin. I don't really see that so much in Ethereum--perhaps I could be wrong.

Then there is the fact that if it goes off PoW there is a whole different security model to consider (worth discussing attack vectors here, because they are similar to authoritarian abuses of power that we already see in oligarchical governance structures in meat space today). If they don't go off PoW, they will always be in Bitcoin's shadow (hashrate)--if Bitcoin fails, the same attack could be used on any other blockchain, with less effort, to shut it down. This is similar to a macro issue with western Democracy as well, which has led to unipolar international politics with The United States at the center (e.g. existential attacks on free markets and Democracy like 9/11 wouldn't happen anywhere else, can you imagine if the attack had been anywhere else?).

See also:

A great read on Democracy, that the point isn't to find the "best leader," it's to keep leaders accountable by always being able to REMOVE them: You don't see this is "proportional voting," which is why in countries like Japanese (where I reside), LDP has been in power basically forever.