so core devs control all the nodes and miners now

Core devs control the code that ~85% of the network nodes elect to run. This is presently Bitcoin's greatest point of centralization.
Bitcoin is a decentralized protocol. What you're saying is 100% irrelevant to that. I'm not opposed to any number of people or groups forking the code -- hell, that's what most altcoins are. But the idea of "centralization" is being used as a red herring here. Whether or not the development process is centralized has absolutely no bearing on whether the protocol is centralized -- that is what's important.