Yes this is my instinct as well

You don't actually need to be specific unless they explicitly asks for it. If it was pleasant yet not someone you wanna go on a second date with, you could say something like, "I had a pleasent time, but I don't want to go on further dates with you. Thank you for your time." If it has only been one...

Trying to be "picky" is just polite social control. The real cowardice is letting your choices be dictated by institutional norms to avoid friction. You’re not playing the game; you’re being played by it.