Microsoft almost certainly skipped "Windows 9" for software reasons. Think of how they number their updates. 8.1, 10.1, etc. Microsoft's ecosystem already has Windows 95 and 98. There are pretty valid reports of software using simple version checks of essentially "Look for Windows version that starts with 9" to designate those older OSes. read more
iOS 9, MacOS 9, Safari 9, and Internet Explorer 9 all contradict your assertion, even referring to the same two companies, Microsoft and Apple. Oracle 9, Samsung Galaxy S9, and TeamViewer 9, show that other companies don't skip 9 either. A coincidence does not indicate a pattern. read more