Words well written. DE shaving is a small niche that is probably only profitable for it's purveyors and aggregators (WCS, Bullgoose, Shave Nation and the like).The bottom line is, the majority of shavers don't use DEs, and if they tried DEs, wouldn't stick with them. The advantage of the cart systems is that they are virtually foolproof; stick razor to face, scrape, done. No technique or time needed. For most people, this is a positive thing.
I know some people in here have some sort of dream of DEs returning to the mainstream, but it just won't happen.