I think that perhaps what you are seeing as judgement is not so much judging you for not knowing ASL, but rather, an indication of how much the language is tied to the culture. It is simply expected that, if you wish to join into Deaf Culture, you will learn ASL in order to communicate with the other members of that culture. They want to form friendships with you,not be your ASL tutor.
It is true that when one has been rejected by their family, it is difficult to understand that there is another group that will accept you as you are. Rejection makes us leary of even trying to form close relationships with others. But, neither is it fair to yourself or others to let what happened with your birth family get in the way of developing close bonds with others.
I cannot recall a single time that I have felt rejected by Deaf Culture. In fact, I will say now, and have always said, that I (and my child) were welcomed with open arms. I went there to learn, and learn I did. In the process of learning a language, and learning what experiences my son would go through as he grew up, I also developed many close friendships that are a valuable part of the person I am today. The only instances in which I have seen Deaf Culture be rejecting is when the other person has an objectionable attititude, and tries to inflict their hearing way of life into Deaf Culture.