The child support saga continues...

I was divorced 10 years ago.  The ex paid rather low child support payments every week for a few years  (which was okay with me, I made good money on my own).  Then the child support payments stopped and the excuses started.  He had a new girlfriend, he had to move, he needed a new vehicle, blah blah blah. 

Now it is 8 years later.  I have a court judgment against him for 8 years of back child support.  He is about to receive a large amount of money, and  I sent a wage garnishment order from the court.  And he's pissed.

Can someone explain this to me?  Why is it that I am the bad guy here?  Am I wrong to think that a man should take care of his children?  Why are some men so selfish?

I really can't stand drama.