True, it'd be interesting if someone did some sort of study on that though, and get some real numbers. I have the impression that people know less and less what the open source definition even is, so maybe this has started to shift in the last few years? I have a feeling, to younger developers, open source means often (in practice): I can see the code, and I can use it without having to pay...
But I think most folks have in mind something more permissive than just being able to /view/ the source. In particular, being able to modify, run, and redistribute are also essential (the fsf's four freedoms get closer to the heart of the matter).
I think "you can't use it to do X" disqualifies the license, though in this case I'm not sure how much I care, since it's prohibiting things that are illegal where I am anyway (maybe if your country doesn't have a dmca equivalent it might matter).