In many situations lord capulet is to blame for his idiotic decisions that no one wanted to agree with, he wa the one to start the feud between montague and capulet.
This caused them to fight and sometimes even kill each other which led to even worse punishment by the princess
The feud also cause romeo and juliet to have strict meeting time due to the families hatred for each other.
Lord capulet was the one that rearranged the marriage that juliet didn't want to take part in, but was forced because lord capulet didn't care for juliet’s opinion