I think there are definitely people in certain regions of the US that would be equally happy to go to either. A state where this might very well be the case is Michigan. If you are from Michigan and want to practice medicine in Michigan I'm sure you are more likely to look at an opportunity to attend a DO or MD school equally.
There's definitely not many people that would willingly turn down an MD offer for a DO school, but I'm fairly certain they exist. A student currently attending RVUCOM said on the most recent school specific thread that he turned down 2 other DO acceptances and an MD interview to attend RVU. Turning down an interview is not necessarily the same thing, but if you turn down a shot at MD then I think that definitely means you would turn down the acceptance as well. With that said, this was clearly due to a particular interest in the school and had it been a different DO school its very likely the decision to not attend that MD interview would have been different.
Personally, I chose to apply only DO, but it wasn't because DO was my preference. Simply put, my app had some low lows that and I feared it would have gotten tossed in the rejection pile at MD schools, but I knew DO schools would see passed it and see my strengths make up for it. The main thing anyone should ask themselves if they're applying DO is if they would be happy in a primary care specialty. If the answer is yes then I see no reason why you shouldn't apply. Most importantly, there was a factor of uncertainty in that I was applying with a new MCAT and whether or not it would be my strong point in an MD application depended entirely on how schools looked at it. I had the choice of waiting a year to see what scores school were accepting and apply early for both or apply late for DO. In the end, I figured that sacrificing a year over something so petty was just not the right choice.
Some DO schools are definitely among the most expensive schools in the nation (AZCOM and CCOM). However, if you're going purely off tuition US News lists 10 of the cheapest private medical schools in the nation and 6 of them are DO schools so the myth that they are more expensive is easy to dispel. They're easily more expensive because they're generally private schools more than that they advertise themselves as though they're selling something proprietary. If you're talking about indebtedness, then yah I'd agree that's a different story, but your indebtedness is typically dictated by a number of things, particularly your background and how it influences your qualification for financial aid.
Regarding the prejudice, it exists to a degree, but is limited to academia/training and is non-existent AFAIK with respect to the general public. That is, of course, unless you count not knowing what a DO is as prejudice. I'm generally not an optimist, but I see the merger as a sign of a bright future for DOs. I may be wrong, but at worst the merger won't make a difference at all. From a rational perspective I don't see why the AOA would agree to something that ends up being bad for graduates of osteopathic medical schools.
Judging by how touchy everybody is getting this does seem to be a sensitive topic. Do DOs feel insecure about their title? Are there any DOs on here that feel the need to prove themselves regularly?
No one here feels obligated to prove anything. In case you're wondering your questions could have been asked in a nice and much less condescending way. The irony is you ask these questions regarding social perceptions of DOs as if to exclude yourself from subscribing to them, but do everything you would need to do to lead people to question your intentions. Your question simply boils down to has anyone chosen a DO school over an MD school and if so why? Yet you managed to ask the question in such a way that you can throw in the word quacks (but its fine cause its in quotations right?) and suggest that the choice to attend medical school is somehow forced on students who go to DO schools. A part of me tells me you're a troll too, but I'm willing to give you the benefit of the doubt and I hope this response is evident of that.