Yeah, and then there are many enterprises that still use XP (edge case, but it may be well hundreds of thousands worldwide still) or Win 7 (possible millions of companies). It is not all smooth sailing in enterprise level either, many companies are upgrade averse, and if the stuff works, then why upgrade it.
If I was not using my PC for gaming also, I would probably say fuck them and be on Linux too. But gaming on Linux is cancer.