Disclaimer: As some of you might know who read my posts, I believe we're in the middle of a long-term economic transition from an old, car-based economic model to a new, internet-based economic model. So my thinking about this is colored by my bias.
So I periodically pore over the terms of service of the various websites I work with to try to better understand them, and yet still I remain confused by certain points of ambiguity. Amazingly, those points of ambiguity remain consistent - for example, if a company uses the term "valuable content," it's consistently vague and ill-defined. Everyone connotes their own meaning from the term, but the concept is in transition (because what's valuable in the old economic model - content that brings the mass market user to a centralized retailer - is not necessarily the same as what's valuable in the new economic model - content that helps users satisfyingly navigate the vast and various landscape of the commercial web). From user to user, the denotation of "valuable content" varies pretty wildly.
I think that the ambiguity of the core ethical concepts is real and is related to the fact that currently, any successful internet business must successfully straddle both the old and new economic models - the old, still being driven staunchly by the profitable baby boomer cohort, and the new, driven rather chaotically by the those who feel most vested in building the new infrastructure.
Which means that when someone says it's "obvious" the terms of service mean X, and someone else says it's not obvious at all - and furthermore the terms are "unfair" or "buried" - it's kinda due to how well people are adjusting, or not, to the shift between economic models - their various strategies for riding out the storm - or even their ability to recognize what's going on.