If you're not interested in someone
Don't date them! If you don't want to be someone's friend, don't talk to them. If you don't like what you see don't look at it. If you have different believes then don't bring it up. Stop putting yourself out there to let everyone know you're against something in particular or no one will like you.
Literally no one cares about your ******* opinion and stop involving yourself in things that disinterest you, you're probably already miserable as it is.