Erzebet- That's not true. People can have bad teeth for lots of reasons. I brush my daughters teeth 2-3 times a day and floss regularly but she still has cavities do to complications I had during my pregnancy which caused her teeth to be very week when they came in. I had a life threatening illness which caused my teeth to weaken and get yellow even tho I took care of them (tho they're better now ). Even something as simple as acid reflux can ruin a persons teeth due to acid erosion that is beyond their control.

#103- on top of what the other two commentors have said, there is also plenty of research (though I can't be bothered digging any out right now) to suggest that dental health also has some hereditory traits. Not to mention that for some people, it's not a case of laziness. I've always suffered from severe depression, and it was especially bad as a teenager (hormones+depression=******). There were weeks at a time where I couldn't muster the energy/willpower to even get out of bed, let alone brush and floss twice a day. You could probably stand to be a little less superficial. I'm sure if people looked on you with the same level of judgement shown in this comment, you wouldn't like it one bit.