I think you're presupposing that principles are interchangeable and I don't accept that. I believe in some inherent human rights, and the merits of this particular issue are incredibly relevant. The gentleman in question made a substantial monetary contribution aimed at denying a collection of people a set of privileges.
The reasons for why society ought to privilege views like his over the rights of other people are flimsy at best; it's just a lousy idea given that the basis is wholly religious. Substitute something interracial marriage if you prefer. The fact is that some views are not just immoral in the face of society's avowed principles but unsound as well.