Am I the only one that sees how conflicted the messaging is in this thread?

In one camp we have people saying that BC is not really centralized because it's free and open source and can therefore be forked and modified in any arbitrary fashion, but then the other camp talks all about consensus issues and why implementations not running the official BC source are a bad idea.

What's interesting about this is the moment you fork the code and start making changes to it, it is also an alternative implementation.  You could argue about the probabilities of forking risk, etc, but the fact remains, the moment you fork it and modify it, you are running something that is not the same as the majority of other nodes on the network.  It would not take much at all for somebody to fork BC and refactor some code while adding some features that they want which accidentally (or even intentionally if it's a malicious actor intending to distribute their fork) makes a mistake that very subtly breaks consensus.  This is really no different than any other alternative implementation when you get right down to it.

It's either acceptable to have Bitcoin nodes running different code bases or it's not.  I just don't see how any reasonable person can claim it goes both ways.  Either the message must be that it's too dangerous to run anything except the official Bitcoin Core sources, in which case the development truly is centralized and controlled by the small group of people who hold the ssh keys, or that it is in fact acceptable to run modified sources (which very much implies alternative implementations).  It's just not reasonable to claim that it's not centralized because theoretically anybody can fork it and do whatever they want while at the same time saying don't do that because it's too dangerous!