The decision to skip a version is a marketing ploy.
Windows 98 = success
Windows ME = flop
Windows XP = success
Windows Vista = flop
Windows 7 = success
Windows 8 = flop
Because of this, MS is skipping windows 9 all-together and going straight to windows 10. It's just all marketing crap.
Anyhow, I really don't care about Windows 10 when Windows 7 works fine for me. Not like it's going to make me more productive.