It's not a very good song, actually - so it was probably clever to release it as a single B-side for the die-hard fan rather than annoy the casual album listener ...
A number 1 hit? It wasn't even considered good enough for an album that only had limited world wide release. Roger knew that The Cross was always going to be a Queen side project and closed it down before fans deserted in droves.
A shame really as I thought Blue Rock was the best of the 3 Cross albums.