Great strawman argument, well done 10/10 for effort!
How exactly is that a straw man?
How hard is it to understand that you can believe what ever bat sht crazy ideas and delusions you like, just dont go publicly spouting them when they contradict your employers position if you want to keep your job or get another one.
On what principle does that ideal stop!
What is stopping the ARU from deciding that instead of firing people once they have expressed an opinion they don't like they simply won't hire Christians (or any other groups that also hold said ideas) because they may hold these ideas!? Absolutely nothing that's what.
And if we're going to allow the ARU and NRL to discriminate (I can't think of a better word for it) against people simply for holding an offensive opinion (so not actually breaking the law or anything), then which other organisations are we going to allow to discriminate against based on the same premise and are who else apart from homophobes we going to allow them to discriminate against!?
For example should the ARU be able to discriminate against people in their organisation that express a different political opinion to them? On principal there's nothing stopping them from deciding to do that from now on, because as a company they don't hold to those opinions and they don't want their organisation and brand associated with that!?
Also if the ARU and NRL can do it then whats stopping e.g. banks from being able to refuse service to people because they don't want to be associated with them/their opinions? You'll say that's a straw man because the people that they are discriminating against aren't working for the banks, but that is BS, because on the same principle you could argue that them selling their services to people associates their business with those people and their opinions (and people have already made that argument, just look at Youtube and other social media sites pulling being forced to pull advertising from certain groups/individuals because the advertisers "don't want their brand associated with them").
But even if you don't accept that premise (which you won't because you're an authoritarian who hasn't perceived of a future where you political ideals aren't held in the majority), what's stopping
any and
every company from refusing to hire people based on their opinions!? Nothing really, nothing at all! So realistically a situation has been created where portions of society that hold offensive opinions or do offensive things that piss off enough people could be rendered totally unhireable!
Like almost all people you're not looking at the bigger picture and you've fallen into a pattern of thinking that people (or at least their opinions) that disagree with you are evil and therefore it's ok if bad things happen to them, and in doing so you've failed to see that once the precedent has been set their is nothing stopping other people from doing the exact same thing to you!