Judgemental has become a negative word because of its implications of "judge not, lest ye be judged".
But of course we all make judgements - using your judgement is an essential part of making sense of the world. We're all judgemental about yobbos spitting in the street, or parents murdering their babies, or obviously bad things like that.
I think you've got every right to to dislike this person if you want to and to be as judgemental as you like! With my judges wig on (quick disclaimer: I am not a judge - that was figurative) I'd say s/he sounds like a bad lot!