Or are they, at the very core, just greedy assholes trying to take all the benefits without contributing back?

It's this. They are the adult equivalent of the toddler that steals the cookies and then tells the parent "I can't be in trouble because those cookies are mine", while blissfully unaware that you have to buy cookies and they don't just appear on the shelf.

"Cookies" in this analogy is the societal contract. I realize that analogy may have been a little dense.