Now it just seems to me as a little ol' predent that this topic is a bit silly.
I understand it as much as I can from my position. I got a lot of **** at my college for choosing dental over medical school from the pre-meds especially since I switched from pre-med to pre-dent (and no it wasn't due to grades or an MCAT score). Most of them thought I was taking the "easy" way out and that I wouldn't be a real "doctor" and at first I got defensive and tried this whole argument. That lasted about a week and I found out something. It really doesn't matter and I really don't care. Life is what I make of it and when I'm dead and gone I'm not going to give two sh*ts and shingle about it.
Everyone (at least all the pre-professionals I know) secretly want others to look at their lives/schedules and think, "There is no way I could do that, It must be so hard, I don't know how they do it." Everyone wants to feel like theirs is the hardest load to bear. I think that's where this argument comes from.
"You don't even know man, my work is like so hard"
I've heard this for everything from Pharmacy school to Nursing and to be honest it's a little childish and ridiculous. Making sweeping generalizations is a bad idea in any case, and the fact that you even need to make a sweeping generalization in order to compare the two fields should set off some bells somewhere.
You can compare Dental School and Medical School sure but they aren't the same thing you can never truly equate one for the other, but just like at my school there are some people
who can't let this topic go. They have to be in the most difficult classes, etc.
None of this is to say, that I think Dental or Medical school is "easy" or that people exaggerate when it comes to this. If I ever (hopefully) become a dentist I'm not going to be one of those people who have to constantly remind others that I'm a Dr. to. (believe me I've met them) I'm not doing this for prestige or for money. I'm doing it because it's the most interesting and legal thing I can think to do and make a living at. I don't need to know that I had it harder in school than the trauma nurse busting her ass after a double shift, or the guy mopping the floor.
To be frank I don't know which one is harder. I don't think you can even honestly judge it due simply to the nature of humans. Even people who have taken both didn't take them at the same time (as far as my knowledge goes) and taking one first may have prepared them better for the other. When it comes down to it "hard" is entirely subjective. The standardized tests are probably the only relatively accurate model but even then you can run into issues.
I realize this probably won't make a difference to many people especially the type who have kept this argument going for centuries? I'll just end it here before I start rambling.
God rest ye merry gentlemen and gentlewomen may you find solace in what you may for on the morrow we die. :|