Why the heck would 2 projects share the same library?
Coming from the olden days, with good package management, infrequent updates and the idea that you wanted to indeed save that x number of bytes on the disk and in memory, only installing one was the way to go.
Python also wasn’t exactly a high brow academic effort to brain storm the next big thing, it was built to be a simple tool and that included just fetching some library from your system was good enough.
So xyz being “morally correct” and saying that, is just that person’s point of view, and if you have a different point of view, it’s just a difference of opinion.