Unless you have the luxury of vast, sparsely inhabited areas such as Baikonur, to avoid wasting fuel and limiting payload, a launching site for space vehicles needs to be:
1. As close to the Equator as possible.
2. On an east coast.
Hence the Ariane site at Kourou is ideal - and is also why the US uses Cape Canaveral.
Prestwick would be far from ideal and Kinloss almost as bad. Quite where a UK site could be based is difficult to imagine. As would be firing rockets up through busy airspace!
Another daft idea from Mother MayDay's increasingly weak and unstable government?