It was, eventually. In the beginning 10 was literally just Windows 8.1 (it even ran the same NT6 kernel) but with the classic UI slapped back on. They called it 10 to get away from the Windows 8 branding that everyone hated.

I recall it being pretty mediocre at release, just a reskinned 8.1. 10 started to come into its own much later after NT10