You called it a fairy tale, do you believe that big corporations are actually bigger tax cheats than small businesses, and they're just getting away with it somehow?
Look at where we started.
Pfizer gets fined more beacuse they are a bigger company and have more surface area, the law is complex and everyone is breaking it all the time so action against them doesn't mean they did anything wrong. In and of itself fine, that may be true.
Then those same people will later say, the IRS went after that Mexican restaurant instead of Pfizer beacuse they are so big, and run such a tight ship that it would almost impossible to find any wrong doing.
The tax code is very complex, so is drug regulation. Is the idea that Pfizer is hyper competent in tax law but incompetent when it comes to the core business? That doesn't hold water for me.