Just looking at it from an average joe's point of view... They aren't going to care about all the economics of it. I think if the average person knew that the products are coming directly from somebody else, or various somebodies... the first thing many people will think, is that they're paying some guy for being a middle man and doing nothing but answering an email... and maybe they can get it directly from somebody else. I'm not saying that's the logical way to think of it, I'm just saying that I would bet many people would view it that way.
Me personally? I'm the wrong guy to ask, because I bust my butt 7 days a week doing everything drop ship people do, then I have to manufacturer all the stuff on top of that.
I've ordered stuff from places that I later found were drop-shipping, and it turned out to be a problem, because it was very unprofessional. I'm not saying all people who do it are bad, but everybody knows there are some bad ones out there... Literally, guys running stuff from their bedroom and don't have a clue about a single product they sell. I actually have guys like that referring customers to ME, because they know so little about their stuff, they can't even answer their customer's questions. So I think it's the 'one bad apple' scenario. Anybody that has been down that road will most likely not have a positive opinion about drop-shipping. Therefore, advertising it... probably not a good idea.