I'm quite aware of the "scams" they were pulling back then. Those "scams" were the ones that were indirectly getting most of the FBs profit.
But I'd kindly direct you to The Worst Argument [1], if the implied shadiness of becoming of Zynga is the argument you're trying to do.
But, along those lines - 'creative accounting' is an example of shady practices which are very creative indeed.
Perhaps you should redirect that reference to your not relevant link to the author of the article that is cited and quoted. You asked why Zynga was getting beaten up so much, you got an answer to your question.
The parent to which I replied edited the comment, so you can't see the relevance.
"A typical scam: users are offered in game currency in exchange for filling out an IQ survey. Four simple questions are asked. The answers are irrelevant. When the user gets to the last question they are told their results will be text messaged to them. They are asked to enter in their mobile phone number, and are texted a pin code to enter on the quiz. Once they’ve done that, they’ve just subscribed to a $9.99/month subscription."