Because people who like guns also like gadgets? There is a huge amount of training necessary to acquire the skills to use a red dot in a defensive situation. Everyone looks to the SOCOM people and trends off of what they are doing but it is necessary to remember that these people train every day. Most people who are carrying for their protection are not going to be able to commit the time and cost to become proficient enough to reliably use one. Add to that the things that can go wrong with the dot itself, from a dead battery to a misplaced piece of lint to a fogged lens and the probability of having a failure at the worst time increases a lot. Red dots are great on the range, I have them and use them frequently. But when I carry for PD, I want equipment that is simple to use and that I can depend on no matter what. For me, a red dot doesn't fall into that category.