Presumably it's a reference to the way peak-usage IE created custom requirements and ignored established standards - partly to undermine other browsers, partly just because they were too big to care.

Chrome defaulted top-level event listeners to passive with no real warning or discussion. Chrome no longer passes Acid 3 like it used to. I'm not a web-dev, but I know the list goes on at some length.

So the concern here, whatever its merit, is that Chrome is now undermining other browsers and changing the web for its own benefit.