How come should there be a power to grab in an open source project? Writing code is power? If no one use their code, programmers have no power over anyone. It is the crowd thinking that they must use so called "core" software give programmers power. But core is not a registered company, neither a trade mark, anyone can call themselves core.
It is possible. You get to control the main implementation (currently Core); i.e. you try to make your own implementation the main one. There are only a handful of people who have Bitcoin Core commit keys right now.
Why should commit keys matter? Git is decentralized, any git clone is exactly the same as core, so the software build from any of its clones will be exactly the same too, it is up to each user to use an implementation he like
Of course majority of the users are IT illiterate, but that does not make them more easily accept one version over another
If the commit right to a specific repository matters, then I think who controls the Github controls bitcoin, Github admin can revoke anyone's access isn't it?