Because nobody is buying them. Talked to one dealer that sold around 50 when they first came out. He kept one in stock after the initial rush and it sat for a year. Said he wasn't going to stock them any more.
Interesting. never heard of that, although I just recently bought a Glock 21sf (.45) and a part on it broke/malfunctioned. It's a new frame design with ambi release, well the release broke, now when you push it in from either side, it stays in and the mag wont fall till you touch it. You also have to center it back before it will accept a new mag. Still waiting on the parts to show up to fix it