I think it boils down to how reputable a person behind a company is.
Pincus has previously made claims that did not portray him in good light. That thing with copycating others and not giving a damn about it. That story will only ruin his reputation and make people avoid dealing with him, either it is Zynga or any next project he might launch.
The same applies to Zuckerberg, who doesn't give a damn about his users (called them "stupid f*cks") and doesn't believe in privacy. I'd personally avoid getting involved in any project he is involved into. And no, I'm not on Facebook.
A sound advice of all times is to watch who's running the business. And advice to you to watch what you do to make sure your reputation stays white. At the end of the day, it's how you are being perceived by others. It's wise not to trust organizations but to trust concrete individuals that govern these organizations.
UPDATE: The situation with Zynga sucks particularly. Recently they were doing rounds in Moscow to hire Russian programmers, stocks were also on the table. Programmers came to the US per H1B working visas. Should Pincus force them to give up stocks, they'd have virtually no options. If they were fired they'd have about 1 week to find new employment or take their ass out of the US. One can only hope Pincus would not abuse their fragile situation.