Given its products and business model, Zynga fading away into nothingness is probably the best thing for everyone.

It very charitable to call the GP's rant "criticism".

That's correct. Which makes me wonder if rant = criticism + emotion? If yes, then he/she who rants does make good for an entrepreneur but only if that quality gets toned and put into action.

I believe there would exist some analysis/research around this already. For there does seem some evidence of great companies been built by people who were hurt, emotional or egoistic about their shit.