The difference is the union at some level ultimately has to answer to the workers who comprise the union, whereas the corporation is ultimately responsible to the majority stockholders who are expropriating surplus labor time from those working at corporations.
yes, and a democratic government has to "answer" to its people ostensibly. ask russians how it's going for them.
unions are just another power structure adding on to the infinite pile of things that are constantly trying to fuck me over as an individual human being. no thanks.
Labor time compensated for by Google excessively well is also labor time where workers are producing wealth excessively well. Ken Thompson had a hand in creating an enormous amount of wealth before he stepped foot in Google. Where does all this created wealth come from? The work done by those who work and create wealth at Google (and the uncompensated primitive accumulation of web content - and the taxpayer funded grants to Stanford and for ARPAnet development etc.)