No matter what people say, how they say it, you cannot be passionate about a job that boils down to checking out someones teeth. For example, a dentist might say that he loves dentistry because you get to deal with children and children are funny at the dentist, well.. why not become a primary school teacher? you aren't in it for the money after all and you get a lot more kids to laugh about.
It is perfectly fine to be in it for the money, or even a balance between the money and some other factor, but to say you are not in it for the money AT ALL is absurd; hypocrites.