No one is forced to do anything, iirc that couple never got that cake. Businesses are free to refuse service to people within protected groups, they're just risking legal action when they do. That's the trade up.
True, but it's also disingenuous to imply you're forced to do something because the alternative to that action puts you in legal peril.
In the same way a factory owner is "forced" to comply with OSHA lest they be in legal peril, you cannot discriminate against a protected group without putting yourself in legal peril. Your freedom comes in the form of opting out of activities that put you in that position, if you cannot help but discriminate against those in protected groups due to your religious beliefs then you should take up a profession where that's no longer an issue for you.
If aforementioned factory owner was unwilling to follow OSHA guidences due to a deeply held personal belief then I think it's a much better outcome they see punishment for that until they opt out of that profession than for us to change the law to allow it.