In my view there should be a better distinction between reality shows like The Amazing Race/Survivor/The Apprentice, those like Masterchef/Hells Kitchen and those like Jersey Shore/Kardashians.
The first group are the reality shows I love, taking a bunch of people and putting them in unreal situations to observe their reactions, with something major on the line (be it $1million or another attractive prize). Essentially you don't need any talent to win them so in a true sense anyone can be successful in them - but the interesting part is how people use what skills they do possess to advance themselves in the competition. I also find it interesting to watch otherwise rational people engage in conflict between each other almost exclusively because of the carrot offered of winning.
The second group does involve some talent (like being able to actually cook) but I find that food reality shows don't give enough conflict between contestants and therefore I don't find them as interesting or compelling as the first group of shows. And those shows like Hells Kitchen which try to create conflict between contestants often seem contrived.
The final group of shows can hardly be classed as reality television IMO. Whilst the characters might claim to be real and the setting representing their reality, I think its basically non-scripted acting for the most part. Rather than playing for a prize of being the last one standing, the goal is to promote themselves and their image (or lack thereof). I think thats where reality television gets most of its bad name from, rather than the jokes about season 100 of Survivor.