So wait, let me get this straight. You're asking if any evidence exists refuting your questions, excepting the entirety of the output of the community dedicated to studying the problem?
I point out that a group of people who are employed primarily by a single source are going to generate opinions that are favorable to that source.
If they don't, they are handicapping their ability to put food on the table. Work can still be found without catering to the primary source, but it's not as financially beneficial to do so.
This happens all the time in marketing. Although, to be fair, those studies are often preceded by a number of more accurate private studies, and only the publicized one is suspect.