I'm guessing it's because of the passenger-side application, routing would be a total bitch. Hence the aftercooler.
91stang has a Novi2000, similar to the Vortechs of course, and made his own intercooler setup and piping. He had to turn the intake around and flip the throttle body upside down. And hack away to make everything work. Imagine how many customers would want to deal with that.
I know. I would not want to flip my intake and re-wire all the other things like the tps, IAC and so on. Hell, even the FPR gets in the way of most intakes if they were to be flipped.
but why not custom piping all on the pass. side? I have seen people do it with what seems to be good results. There are ways of doing this that would involve minimal hacking and cutting. It an intercooler can get temps down to 20-30 above ambient that just means more timing advance and more power, not to mention more boost potential.
I have been wanting an IC for a while but the lack of support for them is discouraging.