There was a time, when not every software had "export to pdf". So, having a "print to pdf" meant installing (often pirated) Adobe Acrobat or installing a sketchy free(ware) printdriver software downloaded from sourceforge.

MS adding xps print driver to windows enabled sharing docs consistently (within windows ecosystem) without resorting to hacks.

I don't know why it didn't catch up. May be it was the general mistrust of anything MS, it arrived too late or it was something else.