I despised group projects when I was a student and felt it was so unfair that everyone received the same grade. I once had a group project for an online class, ???? We had never met and were spread out over East and Middle Tennessee.
With that being said, I have my students in 5th grade work in groups occasioanlly because this is a skill many kids need serious development in. BUT, I do not give grades for group work and almost always assign roles for each student to carry out.
I know 5th grade is not college, but I would have felt much better about my group assignments had my grade been based on my work.
You certainly do not sound like a brat so rant away!