nothing indicated he didn't care about money. AT ALL.
secondly prop joe put omar on to the card game. That alone warrants revenge.
Exactly what I came in here to say.
The thing that we'll never know is what all Cheese told Marlo after he stormed out of that Co-Op meeting. I think a lot of people (myself included the first time it aired) thought that Cheese simply told Marlo where Prop Joe lived, so he could kill him. But if you think about it, Marlo had a lot of reasons to kill Joe. He set him up to be robbed by Omar at the card game, he tipped Omar off about the drug shipment, then after Omar robbed that, he lied about how much of a hit they took, so he could get more money out of everybody in the co-op.
If Cheese told Marlo about all that shyt, then Joe getting hit seems extremely justifiable. Joe schooled Marlo and took him under his wing for all of Season 5, but people forget that in Season 4 the only reason he tried to get in good with him is because he needed someone to run off the New York boys that were stealing all his customers in East Baltimore. Joe used Marlo in Season 4, and Marlo used him in Season 5.
The only thing is, we'll never know if Cheese ever actually told Marlo about that shyt.