My in-laws are judgmental & disrespectful. They will be a bad influence on my son, should I let them see him?

My relationship with the in laws has always been extremely strained because they are judgmental, opinionated, and religiously intolerant. My biggest concern is about how they talk to me in front of my son. I grew up knowing my husband's family and have always witnessed my mother-in-law act condescending and disrespectful to my own mom. It is this behavior I will not tolerate in front of my son. I have already had a break-through with them about this and they flat-out told me to grow up. My husband also talked to them about it and told them that he didn't like the way they treated me as well, but they still refused to see our point. (scarry how my mother-in-law reminds me of Marie in Everybody Loves Ramond!) At this point I cannot see myself ever letting them be a part of my son's life. What are your opinions?