Honestly, I'm surprised more companies don't offer pistols like this in a factory configuration. Aside from the Springfield XD and 1911 which can be had with the smaller lower and longer upper half, I don't think anyone else is really doing this. The benefits of the smaller frame for carry and longer sight radius/barrel for velocity/accuracy are exceptional, so it seems it would be something more popular. But perhaps there's not enough of a market to justify the production costs?
There have been others made as well like the P9 Covert, but for the most part they seem to be made in much smaller numbers. I think many of the companies see no reason to go with a "happy medium" due to the number of other options available (from both them and their competitors). They would serve a smaller group of people, and a company like Glock seems happy with where they are. Plus, who really wants to track 13 different models of the same caliber?
I think they are best suited for custom jobs, or in cases (like the 1911) where reliability comes into question. I do see the benefits, and would probably consider it if I had a Glock. There are so many options for increased magazine capacity/larger grip sleeves, so why not?