If your social circle consists entirely of straight-talkers, where will you go when you need to be comforted? If a putty-person wants to associate with you, but you have a well-established reputation for shunning putty-people and a relatively homogenous social circle... well, then, they'll pretend to be a straight-talker, because blending in is what they do. Eventually the game-theory of this makes you paranoid, which means more need and less opportunity for emotional comfort, which means any remaining infiltrators get more of your social bandwidth because they're better at providing that comfort.

Er, what? What are you talking about? This doesn't happen. Is that something you experience in your life? People infiltrating their way into friendships with you, when they know that their personality traits are something you hate? That must suck. :(

Also, you seem to have missed the distinction between in-principle independently-verifiable fact and self-reported preference.

"You can't prove I hate your pie, so I might as well lie and say I like it."?

No thanks. If that's how you (the hypothetical you, a person who wants to be my friend) behave, then, all else being equal, I don't want to be your friend.