Fussy baby in a restaurant

I went out for dinner with my mom and I brought my baby along. We were sitting down eating when he started to complain a little. It wasn’t even that bad of complaining. This couple across from us was giving me and my son the dirtiest looks. I even heard the woman say this is why she hates kids. Because of his complaining my mom went to get a to go bag. We apparently ruined the other couple’s dinner because as we were leaving they left. I decided to be nice and held the door open for them even though my arms were full due to my child. They looked so disgusted with me as I held the door open. How dare that mother be polite!? How dare she and that baby ruin our dinner!? I should mention that this wasn’t a fancy place. It was Burger King.