sole proprietorships and llc's, which would be the main mode of organizing a small company for donations, are for the most part pass-through to individual income for tax purposes and so would have roughly the same tax overhead (aka 0%) as a non-profit religious entity

also: one could just as easily create a 'x rights activism' group as a tax-free non-profit so why single out religion specifically?

It's a good example and while being around the longest. I'm guessing some people find the comment offensive and so I won't add much more on why.