The tradition of religious texts in conlangs goes back at least to the Babel text in the '70s (and certainly much farther -- I expect Bible translations were very early in Esperanto) and the inevitable Daodejing translations for any new conlang. And, of course, for many natural languages, Bible texts are all that there is (Thank you, Wycliffe and SIL). So, it is not the nature of the items that is the problem, here. It is probably partly that there is so little other sorts of text, and partly the unfamiliar nature of some of the sources (or, apparently, the exact nature of those sources, though Bahai'i seems unfairly tarred here). The American conlang community inevitably sees a lot of Bible work and very little Koran, but there is more of the latter on an international level (though still not so much as the Bible or even some other religious texts).
Personally, I am more offended by the space wasted (my judgement, of course) on sign language (which is only remotely likely to be significant for tp) and "hieroglyphs" (for a fringe element of the conlang world -- my judgement again, of course), when interesting and even pressing issue in the language itself are unaddressed, even though they have been raised on various forums often over the years. Well, and 'pu', of course.