Amongst Siggies, there seems to be a great affection for the classic, all-metal, double action/ single action designs, such as the 226. Further, many of them detest the company, now that that guy Cohen is leading it. The P250 IS different - very different from that which they are familiar. The DAO trigger just ain't like the 226 trigger.
So, I think it is a combination of all of these factors. Call it traditionalism, mixed with an instinctive fear of new things. (Kind of the same thing, when you think about it.)