In a capitalist economy, it is all to common that corporations, companies, and the media exploit the underprivileged to drive up profits. Much as companies try to minimize payments to their workforce for the greed's sake, sensationalist media showcases stories that drive up their viewership without a thought to the people whose stories they are using to do so. Reality television is perhaps the worst example, earning money by showing the worst (and therefore most entertaining) of the people they film. Of course, these people give permission, but is it surprising that they would? People in those situations often are in desperate need of money, and will sell a disparaging story in order to do so. In the long run it is rarely worth it for these folk, and it is the media company who pockets the profits while the people they filmed fade to irrelevance if they clean up their act - this in a way encourages the negative behavior which perhaps got them in the situation they were in to begin with. This vicious cycle benefits only the media, and the people they film are left by the wayside if things go south.
I have to admit, I had to Google Don Vito Margera's name to know who he is. I do recognize him from the popular reality show "Jackass". He was known for being Bam's father, and Bam always would wake him up in the middle of the night punching him. This is really sad that he passed away at only 59. I don't know if the question directly relates to Margera's recent death, but I do agree that reality shows are extremely exploitative. Some of them take it too far and are too invasive in these people's lives. They also stretch the truth so often, it seems they are almost 100% fake these days.
Reality shows unfairly exploit those who star in them. Granted though that most of those who star in reality shows do sign a contract. Reality shows are in it for the ratings and the money that they can earn, not the emotional and physical well-being of the stars. If there is not enough drama going on a producer will find a way to add some, whatever the consequences to the "stars" may be.
20 years ago, reality TV was still a novelty and a bit off putting for many people. However, in the current decade it is a television staple. While there have been controversial shows that push the boundaries of what is ethical, such as "The Briefcase," many shows portray a unique event or characteristic in the lives of an average person, for example "Hoarders," "True Life," or "American Idol." At this point, the people who agree to be on these shows know what they're getting in to and are making an informed decision. Exploitation implies that there is a victim, or someone who doesn't know the repercussions of a decisions or has no other choice. And while this may be true for some people who agree to participate, I would argue that the majority of people are aware of the risks.