That's one of the issues I have. I've gotten into affiliate marketing as a way of getting some extra income. As such, I'm extremely wary of this thing reporting that information to Valve. They have no need to collect it, nor do they need to know:
I could fill dozens (if not hundreds) of pages with things they have no reason to collect. I've read their privacy policy, and it's very good. It's heavily geared towards maintaining the user's privacy, but I do have problems with it. Under certain circumstances (which they don't elaborate on), they will share their collected data with affiliates (whom they don't identify). When that happens, what is done with the data is determined by the privacy policy of the affiliate, which I will not have agreed to (since I have no clue who they are). While this is a standard practice with many, many companies, I still find it very disturbing that, within months (if not weeks or days), the information that Valve collects could be in the possession of hundreds or thousands of companies whose privacy policies I haven't investigated or agreed to (and whose databases may not be as secure as they should be).
I find it highly objectionable for Bethesda to require us to submit to this just to play their game. Granted, this is supposed to be a method of preventing/reducing piracy, but it doesn't come even remotely close to working. Just look on this Nexus forum and do a search for Piracy, Vegas to get an idea. There are at least 130 now banned users listed there, and that's just the ones dumb enough to openly admit they pirated Falllout: New Vegas. Clearly, requiring Steam does absolutely nothing to stem piracy. All it does is compromise the privacy of those who purchase legitimate copies of the game.
As good as Bethesda's games are, I'm just not willing to submit myself to this in order to play them.