I think the video is ridiculous and hope they get a lot of bad publicity out of it.
But I think I see what some are trying to say. When a baker doesn't make a cake for a gay couple it is discriminatory. The cake is tangible and has been made for many straight couples. Therefore it should be available to anyone who wants a cake.
Paradise is a made up place, that you get to with (ever changing) made up rules. And no one can ever prove that a straight person made it to paradise and a gay person did not.
So it's not okay to discriminate in real world situations, but we can all have whatever made up rules, affecting made up places we want.
Do I have the argument right? Just trying to understand,not trying to start a shit-storm.