That's an idealised position, but not always a realistic one. Having specialists who understand certain parts of a complicated system better than anyone else is

That's an idealised position, but not always a realistic one. Having specialists who understand certain parts of a complicated system better than anyone else is often valuable. Beyond a relatively small size of project, no-one can be an expert on everything, and a "shared code ownership" strategy where all code is communally maintained may leave you with no true expert when you need one. The underlying problem here wasn't really that someone "owned" that code, but that when someone else did have a useful suggestion to make, politics overrode technical merit. Clearly that had been happening for a long time and resulted in several other potentially useful contributions by others being wasted as well. This seems to be a problem of toxic management culture, not a flaw in the technical processes.