Race, religion, national origin, sex, these all apply regardless of which specific group you're in under that banner. There are a few categories which are really only defined as applying to "one side", but they're generally not controversial (the laws against pregnancy discrimination, for example). Age is the one big outlier: the law against age discrimination in employment applies only to people over 40.
No judge in the developed world would believe such a contrived excuse.
It's weird how people think this sort of thing is actually a valid defense.
How can I tell that person is an asshole who meant to hurt my feelings vs that person who just said a stupid thing without thinking about it?
I can't, so the reality is that some subset of people are going to get away with hurting my feelings on purpose. The alternative is that people who make mistakes get punished unnecessarily.
Which side of that would you rather the law be on?
That's not what "protected class" means, in any of the contexts in which it is used (employment, public accommodation, housing, etc.)
To the extent it seems like it means that, that's only because, well, the historically privileged are more likely to be in a position to discriminate in favor of those like themselves.
In each of those contexts, race (not "being non-white") is a protected class; it is just as illegal to discriminate against White people in any of those contexts as it is to discriminate in favor of White people.
For each of the other descriptors which actually relates to a protected class, it works the same way where it does.
> It's far fewer words with the exact same meaning as listing all the things that are 'protected', and has an air of honesty about it.
It doesn't have the exact same meaning at all.