I am 100% sure there are MANY that are in MD school that do not fit this bill (Read "Becoming Dr. Q" if you need proof). However, I personally know many more that fit this description that are going to MD school, and EVERY person that I know who is at DO school is either from more humble circumstances, or is non-trad and is truly passionate about helping people.
I dont think it would be a night and day difference, where like MD's cast a dark shadow down hallways that they walk through, but I just think that the nature of the process of even getting into these perspective types of schools have different standards for what types of students that they are trying to find.
So I dont think it should be set in stone that one is better or more empathetic than the other, just a slight difference based upon the nature of the application process and the teaching differences at the schools.
But then again, this is just another n=1 from a pre-med