This isn't a scene from the "Housewives of New Jersey," is it?
Just kidding around.....
Seriously, as others have said, 'some' drama will always be present if for no other reason than there are other people in the family. No one sees eye-to-eye on everything. I think it's how you deal with it that makes the difference. I agree with you that if it isn't dealt with at all, then people accept it as normal even if they still don't agree with it. If NOTHING is ever said the instigator will continue to bring drama until they are shut down....in some cases, they have to be ganged up on by many family members or they will just blast one person's point of view, as you experienced. I also agree that is a learned behavior. The more the younger generation witnesses it and sees that it is....accepted or, at least, tolerated, they, too, will probably exhibit that behavior.
My 'drama' came early in our marriage. I was 20, wife was 18. I had joined the Navy and had moved to San Diego for training and later where my ship was stationed. My MIL would constantly tell us what we should or shouldn't do, how much money to spend or not spend, blah, blah, blah. I would rant about it to my wife. I finally wrote my MIL a letter and told her to stop. We are now married, we are trying to live our lives and while I would appreciate 'advice', I didn't want to be TOLD what I have to do. Quit thinking of us as children. Yeah, we didn't talk to the inlaws for about 6 months. BUT....when we did finally, amazingly, things were much different and we got some awesome advice and suggestions. Since then, we have had a great relationship. That was over 35 years ago.