It’s nothing to do with religion. When you fetishise identities you don’t belong to, it can be helpful to listen to people who belong to those identities, so you can fetishise us respectfully. Otherwise you’d be talking about having sex with people you won’t respect, which I’m sure you don’t want to do.

If I were to tell you to use all caps when referring to ME, would that be reasonable?
What about all lower case, even when starting a sentence?

Sure. My goddess-mother’s name was fractal, all lowercase. Even at the start of a sentence. Even when yelling in all caps. It was easy to do and made them happy.

Valuing the rules of grammar over people’s feelings seems like a very unusual choice. Personally, I think language should exist to help people, not the other way around.

I use capitalised pronouns because I like them. That’s what the article explains. The reasons that people like their preferred pronouns don’t tend to go any deeper than that.

Maybe a story will feel more complete: 4 years ago, while My goddess-mother was helping Me understand My gender, She suggested I try out capitalised pronouns. I did, and I liked them. As good as she/her felt compared to using he/him, that’s how They/Them felt compared to she/her. I liked them, so I kept them.

Here’s an explanation of My pronouns: https://medium.com/@viridiangrail/introduction-to-capitalised-pronouns-f5140e722b48