I think this is the key point in order to answer your poll, and that's probably the reason why right now you have almost 50/50 results. It all depends on this point of view, and maybe you should consider deciding what perspective should we use before voting. I voted yes, because I'm considering that being mainstream doesn't need adoption as well. Like you said yourself, it's hard to talk to someone that hasn't at least heard about Bitcoin, even if they don't know what it is, and for that I think bitcoin is already mainstream in terms of awareness. It is not mainstream in terms of adoption though, and that is easily checked if you look at Bitcoin price.