I thought all of these died out in the 80's when most were born. I had a boss at the time who thought that one of these would prove effective - at least in reducing the development burden on the Department. Those that I tried all proved fantastic when applied to tasks very similar to those shown in the demos but quickly proved more complex than standard programming (using a 3GL) when applied to anything but the most trivial task.
A bit like report writers - marginally quicker than hand coding for straightforward reports but wildly complicated when things got tougher or the users asked for 'just one more feature'.