Honestly, I think everyone has unrealistic expectations on Patty, yes, he's not the greatest defender, and yes, he'll probably never be a consistant starter in the NBA but that's fine. It's a league filled with guys who've carved out great careers with incomplete games. Patty's role is to be a spark off the bench and to put points on in a hurry which he does well.
There's probably less than 10 guys in the NBA who don't have a height advantage over him, so of all the people on the planet who are 6 foot or less (circa 90% of the population) he's one of the ten best at playing basketball. That's bloody good.