I can only think of one instance where I met a Jew who disparaged converts.
Her name was Sherry. It was an Aish Ha Torah event. And she just came out and said, “I don’t accept that you can convert to becoming Jewish. You’re either born it or not.”
I was so blown away by her comment that I’ve not forgotten it in 17 years.
I don’t think she’s religious because a religious Jew would be less likely to say such a thing. A secular Jew whose Jewish identity is primarily ethnic is more likely to say such things.
Now, I understand the skepticism towards converts shown by many Jews. How can someone take some classes, pass some tests and suddenly become Jewish? It seems too easy. Jews are a prestigious group with a history of persecution and some newcomer can come along and claim membership? What about earning your way?
I was talking about this topic with a friend who’s a convert to Judaism. She tells me, “I’ve never encountered anyone other than this one douchebag. Jews have been wonderful to me quite frankly.”
“This guy I was getting set up with found out I was a convert and said really awful things about me and about converts and how he wanted nothing to do with them. What pissed me off was that I thought he was a dud and was only going to go out with him to be nice. Sucks to be burned by a dud.”
I understand Jews who don’t want to date a convert. If you’re Orthodox from birth you will probably have more in common with someone else Orthodox from birth.