It's a law against offensive speech. If more people in the UK are offended by trolling gays than by trolling Catholics, you don't need a conspiracy theory to explain why one gets you in more trouble than the other.

To clarify, I don't agree with the law - I think offensive speech should be legal - but this Ayn Rand stuff just sounds petulant in this context. If you want to insult gays on social media as a hobby, the main thing stopping you is not government oppression, it's the fact that a majority of voters want you to not do that.