Tony's treatment of Vin

It was quite clear from Tony's treatment of cop-on-the-take Vin Makazian that he regarded him with utter disdain. I always chalked it up to the fact that, despite being quite the hypocrite most of the time, Tony respect people that honored their duties and responsibilities. In that sense, he saw Vin as more or a rat, whereas he treated Agent Harris with much more respect even though he was technically trying to put Tony behind cars.

Anyway, for all the valuable info Makazian provided to Tony (like Big Puss cooperating), I would have thought he would have been a little more grateful or at least pretend to be appreciative/friendly with the guy. I know he also thought he was a degenerate gambler, but at the same time that also made him a customer whereby Tony presumably made money there (and likely forgave some the Vin's losses for info). He basically treated the guy like dog shit the entire series... What else was there that made him hate Vin so much?