I think it depends a lot on who's saying it and what picture triggered the comment. If someone who has a P&S but really likes photography and is thinking about buing a DSLR sees one of my sharp portraits with shallow DOF, he/she will instantly see that I have a great camera....if they know even more, they will know that its is my lens that is good.
I don't blame them for crediting the camera. I don't think we should read too much into it. Obviously they liked the picture (as well, and not just the IQ and shallow DOF). It's just that their minds are so busy thinking about great cameras and lenses that the first comment is about the camera.
If I see a thread title saying "Portrait with DA*55" or "Landscape with DA12-24" I click that link with a lot of prejudice (and LBA) I must admit....
Then I say to myself: "Nah...it's just because he/she is such a great photographer", and that way I keep from spending all that money
But of course there are a lot of people out there with no clue who thinks: the more money spent, the better the picture. I choose to ignore them. There is no way you can make them understand anyway