Yes and yes. I am in the Google contributors data. Some code I contributed is included in all Ubuntu disks. I didn't contribute a lot of open source code, but I do write my own code almost exclusively Open Source as well.

Forking was frowned upon before Github. It's not something you do willy-nilly. Still it's the ultimate security mechanism. If something doesn't work any more the way you need it to be, you can fork it and maintain it the way it used to be. That happened with HIVE. We rely on a specific way of functioning that with Justin Sun has gone. So you can disagree with the reasoning, but for all means and purposes, this fork is fully justified.

You are right that forking a blockchain and forking a repo are different, but they happen for the same reason: in case of disagreement with the direction of a project to make sure that what you RELY ON still is there. That was the reason for BCH, that is the reason for HIVE, that was the reason with LibreOffice, all of those which I have watched develop from the start, all of them fully justified. Yes, they get some slack for doing it, but you can see with the amount of support they get that they fill a need.

So yes, that's why it's possible to fork something, and yes, even though the effect seems very dramatic, it's very necessary too.