Marriottmillionaire,
Although your dates will fall at a busy Spring break time, I wouldn't be overly obsessive about the rowdy crowds. I think that the 2 Marriott hotels in Cancun are expensive enough to ward off most of the college crowd. Also, those properties don't tend to attach themselves to any packages or deals which would more likely be sought out by packs of ambitious vacationing students.
That will not, of course, mean they won't be on your plane flight, but that is the trade off for going on Spring break.
As far as Cancun's appeal, I firmly believe that each traveler is unique and has different criteria as to what they want to do on their precious time off. Most people going to Cancun know that it is a tourist area and are not expecting to have a secluded beach to themselves. Taking into account that Marriottmillionaire is from Denver and looking to take 2 teenagers to a warm climate for Spring break, Cancun seems a perfect choice for him on this trip. I don't think the choice of Cancun has anything to do with a persons previous travel experience, more with the type of activities you want at that time. I would imagine that it's a good thing that we all don't like to take exactly the same vacation as everyone else year after year, or we'd all be going to the same place,and imagine what havoc that would bring!