The issue is what else we could be doing with our time. I personally don't enjoy devoting nearly every weekend to constant study and waxing up dentures like I'm doing this weekend. I don't enjoy spending my weeknights studying while my wife and kids are downstairs without me. I don't enjoy the stress of being an office manager, lab technician, hygienist, and secretary all rolled into one during clinic, all the while scrambling to achieve requirements and deadlines through the random patient base I'm assigned.
Meanwhile, I could have taken a decent job after college, and I could be spending my nights and weekends with my wife and kids, and my stress levels would be significantly lower during these 4 years.
Naturally, my future and my family's future will be much brighter than if I had done the above, because I will be in a profession I enjoy more, we will have a higher standard of living, and will hopefully even end up having more free time than I would have with some other job.
Dental school isn't a grand old fun time; it sucks compared to a lot of other ways I could spend my time. It'll be worth it though.