Most people are not legal analysts. Your snarky characterization of this overlooks the fact that what can be anticipated at the time consent is given may be overtaken by technological developments, that corporations often structure their activities legally so that 'research' is non-commercial even if it is intended to be used later for commercial activity, and that it's polite to ask before doing something you might hesitate to grant consent for yourself.
People need to be able to say: "oops, undo this permission thing that I clicked OK to, as I now better understand the ramifications of what I clicked ... and I don't like it"
There's also a lot of rules to try and make sure the person really understands what it is they are signing up for, with mandated forms etc. And then as you say there's still a cooling off period.
