There is a simpler and less gay-unfriendly explanation to why Hammer never hired Peel again. BRIDES didn't make the kind of money HORROR OF DRAC did.

Hammer had a long-term (non-exclusive) relationship with Universal from late 1958 onward (and a similar one with Columbia). The Dracula sequels were stewing even as HoD continued to rake in money. Initially they were vague ideas (Dracula II, Dracula III, etc.) which solidified (or ossified) over the next couple of years, as financiing/distributing companies would OK a budget.

None of the Universals made a huge amount of money-- Werewolf, Phantom, etc. They made more than the films cost, yes, but they were never the outstanding box office success of the first Dracula.

Eventually Universal droppped their association with Hammer (as did Columbia).

And with regard to Peel's BRIDES being his only starring role-- well, he was a working actor for at least 10 years to that time, on stage, radio and the BBC. My guess, based on the LSoH interview-- he was just tired of it and moved on. No homophobia involved.