Kosher laws are very well-known and established in the Jewish community. It’s also written down in plain english black and white in the old testament. Don’t Eat Pigs. They’re very strict about ALL of them, so it’s something to be taken quite seriously.
By comparison, the “christian” rules that corporations are standing behind to avoid doing business with gay people, or covering women’s health care, aren’t really rules. I don’t think there’s a bible passage that says “Don’t Abort Babies” or “Don’t Marry Someone of Your Own Gender.” And anyway, they don’t follow all the rules they have to begin with, so they’re arbitrarily picking and choosing which ones to get in a tizzy about. You don’t see any Christian Clothing shops refusing to sell cotton/poly blend clothes.
It’s funny that you mention this, because as a gay man who has worked in several print shops as a graphic designer, machine op and pressman, I’ve dealt with this first-hand. In copy shops we would tell the person to go use the self-service machine, but we wouldn’t reproduce the material ourselves. In print shops where we didn’t have the self-service machines we would refuse the service on the grounds that it was offensive material.
The bottom line is that the laws we have in place are there to protect the minorities from being overrun by the majority. The Straight White Christian Man is clearly in the vast majority and thus doesn’t need the protections those laws provide, and in fact, is the reason most of those laws were created in the first place.