Look, on paper I agree with you, they can't claim 'fair academic criticism' and censure papers without explanation. But in the real world, Google has an outsized contribution to AI. They are also a company, and need to pay for all the expenses. There are practical, day to day concerns that are essential for their existence. If they can't ensure their finances, the research program stops. So you can't really be absolutely impartial, just 99%, from time to time you make an exception to impartiality. It's like light speed, you can't reach it.