I frequently come across Windows programs that bundle in MSVCRT (or their more current equivalents) with the program executables. On a typical PC, I would find many copies of t
Programs are linked against a specific version of the runtime, and that required version is not guaranteed to exist on the target machine. Also, matching up versions used to be problematic.
In the Windows world, it's very bad manners to expect your users to go out and find and install a separate library to use your application. You make sure any dependencies not part of the host system are included with your app.
In the linux world this isn't always as simple, since there's a much larger variation for how the host system might look.