The thing is, a lot of the legacy backwards compatible stuff that’s in Linux is because a lot of things in Unix were actually pretty well thought out from the get go, unlike many of the ugly hacks that went into MSDOS and later Windows and overstayed their welcome.
Things like: long case sensitive file names from the beginning instead of forced uppercase 8.3 , a hierarchical filesystem instead of drive letters, “everything is a file” concept, a notion of multiple users and permissions, pre-emptive multitasking, proper virtual memory management instead of a “640k is enough” + XMS + EMS, and so on.
Unix was designed for mainframes, qdos/msdos was designed to be a cpm knockoff the local nerd could use to play commander keen and do his taxes. It’s actually impressive how much modern/business functionality they were able to cram into that.
It still amazes me how well thought out unix was for the era when computing was in its infancy. But I guess that is what you get with computer science nerds from Universities and a budget for development based on making a product the goal, not quarterly profit the goal.
