My impression is that its success stems from the fact that it doesn't claim
to be a programming language (the documentation explicitly states that no
programming experience is necessary) and so doesn't scare off computer users
who have an idea for a game but are somewhat afraid of the idea that they
would have to become a programmer to actually write that game. After all,
AGT didn't grow up in the Internet but in BBSes and the GAMERS forum of
CompuServe, where many of the users are less technically minded than the
crowd around here.
Just my 3 Pfennige. :)
Volker