So, I don't take an "all or nothing" view, but I genuinely understand where you're coming from. I just don't think it is a "dirty secret" (not with this crowd anyway)
Edit - I'd like to add or underscore that I agree with what you're saying that ToS can change at anytime, etc. My emphasis is on how companies treat and talk to their users. I don't think all cloud services should be painted with same brush, they should be judged on their own merits and how they do business generally. A Facebook-owned Instagram already made people nervous. This change in ToS brought back memories of other unpleasant changes.
2nd Edit - Munroe's comic ends with the idea that it's useless to complain or drop the service. Clearly it isn't because Instagram responded and reverted back to their original ToS. They need users too. They acknowledged that they heard them. The joke misses or ignores that fact.