> "What Windows users know" doesn't mean that it's a good thing.
I know (I also removed it). It's patently stupid. Let me rephrase it if you want one way of distributing apps that anyone can use, it's basically the only working way. Download a binary from the creators' site. Otherwise you end up with the utterly broken method of "check if it's in a tree in some package repo, if not, you can add more package sources to your repo, or if not, you check if you can find a downloadable package for it, if not, you build from source".
> Tell me how Windows programs deal with updates to critical libraries that everyone uses separately
They don't. It's both a bug and a feature. OS libraries are updated of course (by windows update) but I don't necessarily consider e.g. a C++ runtime to be an OS library, even if it's microsofts' own redist. I prefer my applications to ship their own copy of their c++ runtime and keep it local because it limits problems. Even at the cost of having an unpatched one somewhere.
> Windows users also know to run everything with administrative privileges.
Well, accidentally answering "yes" to the UAC prompt is about as likely as accidentally sudoing something imo.