That kind of dogged persistence helps when doing a startup.
The IIT-ian you need to watch out for is the one that keeps reminding you that he's from IIT. This kind of guy has usually not done anything else with his life.
Sridhar Vembu of Zoho went to IIT-Madras. He aint doing too bad!
So IIT helps but you certainly dont have to be an IIT-ian to succeed. Some day I hope to prove that :P ...
The only negative "opinion" that I have about IIT-ians (from the ones that I have met) is that they are very good at solving clearly defined problems but they have a hard time defining the problem itself. Ie they have a hard time figuring what the problem is in the first place. If you can give them the problem, clearly defined, they will solve it for you.
(Again this could just be my prejudice :) ...