I believe it's just a classic case of mixing literal and connotative meanings of phrases. The poster does not mean Peter Thiel is inherently an unlikeable person, but that the poster himself believes Peter Thiel to be an unlikeable person, i.e "I don't like Peter Thiel."
E-prime doesn't have this problem.
Now, that sounds insane and unlikely. However, I've seen it mentioned a number of times. I guess the claim is that it is from an interview. I'm unwilling to invest more time to look into it. I don't actually care and I'm not sure why, if true, it would make him a bad person. I have to assume it'd be voluntary, if true.
To be clear, it sounds rather unlikely. I share more to show what folks are saying, than to pass any judgement in his character.
I was able to find two vanity fair pieces on the topic, if only because I had a better place to start: "Thiel blood boy"