Telemetry, my dear Watson.
Sorry, couldn't resist. I think actual user data can be significantly more useful than feedback forums for bettering games. Seeing kill stats, achievements, and other milestones can provide much more to developers than subjective experience relayed during a heated forum discussion. However, data isn't entirely reliable as achievements can be doctored by cheat engines and exploits, and anti-cheat can be bypassed or outright destroyed.
I concur. One such example is with Mr. John Ebenger, formerly of Mass Effect, said that only ~8% of users went into the Renegade content which they "put a lot of work into the [...] content too :(". If the intent was to shame it backfired, because statistically most people don't like being nasty even in video games and this isn't going to help. However I still found the statistic interesting all the same, and wouldn't have known that if not for them stating such on Twitter. But then don't try to guilt trip people into using the Renegade system; instead make a better system.
One thing I enjoy is in episodic games you're often shown the choices players made, which sort of gives away that most choices don't matter. In Sherlock Holmes: Crimes & Punishment you can see the player stats at the end of each chapter, and they're suspiciously skewed to look exactly like my results which came from a guide for easy achievements. Hmm....
Developers and publishers must be prepared to accept that they can't know how good their game is until they release it into the wild. That goes for Atlus flagging Persona streams and Let's Plays incorrectly for copyright claims due to spoilers. That goes for Ubisoft having review scores updated after microtransactions are added. And that goes for BioWare for not seperating morality from social attitude in Mass Effect. By all means they can collect data, but they can't complain when the data goes against their expectations. Ours is a fickle demographic, and is all the better for it.
I don't think we can escape data collection without turning off our internet, changing our phone numbers and directly addressing our mailing lists, but we can do more to be wary of it, and I believe there can be fights for legislation over what data is harvested, how and with what consent from customers. ^^