I am very judgemental and I've found through looking at this in therapy and one important thing I've learned is that judging is a thought stopper, for whatever reason. It might be the mind attempting to be efficient, so something is judged to define it and delcare it unworthy of any more thought; or so perfect that more thought isn't needed.

I think when judging is applied to feelings it has to do with shame. Shame for just being. For me, feelings were not discussed when I was growing up. The only person who mattered was my mother. To her, others were just a means to an end, to fulfill one of her needs or goals.
So, growing up and not having our feelings named and validated, and/or having our feelings invalidated as something we "shouldn't" have (for example having tears responded to with "What is wrong with you?!"), having our vulnerability used against us.. I think causes shame that carries to our feelings.. about our feelings.

It takes a lot of practice to not dismiss by judging. I may never get there, but I keep trying.