I think preventative maintenance is a big player, as well as knowing some basics about the technical aspect of your machine.
Dealers offer good support, but understandably they can only give you so much info/knowledge without you pushing for more.
You also find that on this site, there are many who opt for a cheaper second hand alternative, which offers no dealer support. These buyers are also the more cost conscious, who are reluctant to pay for proper tech support and think that everything can be fixed in house.
Although this may be true for some people, it is not the case for the majority of users, and can be a costly learning curve for the others.
In other words, if more people read their manuals, followed procedure, used trained technicians where required and had more knowledge about the whole process overall, there wouldn't be so many problems.
Recently I went to a print production training session run by 3M. The parts I already knew about were great anyway as it's always good to have a refresher, and I also learnt a few new things as well which gave me more of an appreciation in regards to what one should expect from their printer/media combo.