Someone might be able to look at the script and see if there's any obvious problems with it, but there's not many people who use it here. Most people use ISBoxer, with some using things like KeyClone or HotKeyNet. There's probably more people here using things like Synergy, Plexer or CloneKeys than AHK.

As to why, I couldn't really say for other people. I know from my own experience ISBoxer is very powerful all around and KeyClone is easier to use for newbies than a script-based program. I chose HotKeyNet because it seemed cleaner and more powerful than AHK.