But you can see how it could become centralised if development is centralised and you start trying to tell people what code they can and can't run. Telling people what code they can and can't run is authoritarian. There is literally no denying that. Either trust the open market, or stop pretending you're a libertarian.
Nobody puts a gun to their head and forces them to use 1 version of bitcoin.
The number of coins someone holds does not correlate to the amount of "expertise" they can demonstrate. I don't care if they hold 1 coin or 1 million. If they can't demonstrate the simple understanding that anyone is free to modify and run the code they want, they have no expertise and invested poorly. And again, they should stop pretending they're a libertarian.
But at least they have steak in it, and demonstrate long term loyalty since they are invested. Contrast that with the millions of other BTC users who hold barely coins and could flip-flop between ETH and other currencies, while preaching gospel to bitcoin users.
They should hardly have authority, only loyal bitcoin users should.