Discrimination based on sex/gender is one caveat which I will concede may have a legitimate purpose in some very specific circumstances, such as a gym exclusively for women, as well as other things like restrooms and locker rooms. But outside of those three things, I can't think of any other situations where sex-based discrimination would be permissible.

Are you trying to say that the fact that same-sex couples cannot reproduce with each other somehow proves that homosexuality is not controlled by biology? That's a pretty ridiculous claim...

When a business is open to the general public, the business owner agrees to submit themselves to certain regulations, which include interacting with any and all customers who walk through the door. It's part of the social contract. Lawyers are a bit different because the service they provide isn't just a quick sale of a product, but an extended interaction which can potentially last several months. Besides, you don't want to have someone defending you when they don't already agree with your case, anyway.

And I don't think having the losing side of a court battle always pay the legal costs would necessarily be a good idea. There is already a legal procedure through which that can be done, but it has to be specifically applied for, and the judge has to approve it. Making it happen automatically in every case would cause very big problems.

Because that criteria is not an immutable characteristic controlled by biology. There's nothing wrong with having clothing requirements, because anyone can put on clothing. However, there IS something wrong with having genetic requirements, because people cannot change their genetics.

Yes. Yes I do. I want you to go out and find scientific evidence irrefutably proving that being loud and obnoxious is a biological condition, and that individuals afflicted with it can do nothing about it. I'll be waiting... ;)

A force user to ensure all businesses are available to all potential customers?

A force user to ensure all businesses are available to all potential customers?

So would that make the shop owner a Viragoist?

Does a "female" gym have the right to prohibit males?

or unwilling/unable?

Wanna bet?

Not at all - ever see a sign "No shirt, no shoes, no service?" Why should that proprietor get to establish criterion and another is not allowed to establish their own criterion?

Of course not. I believe I've clearly stated in previous discussions that there is absolutely nothing wrong with throwing customers out for bad conduct. It's only immutable characteristics with a basis in biology that should be protected. Seriously, civil rights issues are not that difficult to understand...

As far I'm aware, being loud and obnoxious is not an immutable characteristic controlled by genetics or biology. :P

Unfortunately, it's not possible to eliminate frivolous lawsuits without eliminating lawsuits entirely. But if you were to eliminate the ability for citizens to file lawsuits for anything at all, that would cause a whole host of other problems where people would have no ability to seek a redress of grievances, even in legitimate cases. You have to take the good with the bad.

Oh, and no, commercial property is very different from residential property. One is your personal space, and the other is open to the public, so naturally the regulations for each are going to be different from each other.