I assume you allow everyone into your home, no questions asked? Maybe you do, but frankly most people at least vet their guests through a combination of social connections and history, and rarely is a place "entirely open" or "entirely closed". Being excluded from a place because the gatekeepers of that place prefer the company of someone else who doesn't like you is perfectly normal and ultimately they have to make a choice between you being at an event or their closer friend.
This isn't to say I agree with every banning or exclusion, but it's perfectly normal behaviour.
I'm old enough to remember reading about netiquette.