Why do people hate margaret?

I see that a LOT of people hate margaret and call manipulator and blame her for ruining mordecai's relationship with c.j, but i think that's really exagereted and it's almost a concent between regular show fans that she is a bad person. I don't think it was wrong that she choosed to got o college instead of mordecai and most of the relationship issues were all mordecai's fault in my opnion. And this people always think c.j didn't nothing wrong, even if she tried to kill margaret's parents. What's your opnion about it?