I know that a lot of people in the UK bought inquisitor models at some point but the game as a whole failed to become popular. Its still available to buy but it never took off and has become a redundant part of the GW website.
There wasn't enough variation in models on offer from GW. They should have forgotten about metals and instead designed a generic plastic kit with lots of choice for variations , like different heads, weapons etc. GW promoted conversions of the metal models heavily in white dwarf but there was a limited amount of conversions that could be done and it wasn't easy to do. Finding components to convert the miniatures wasn't because they were the only ones making sci-fi models at this scale. Only at the end did GW bring out blister packs of components when it was too late.
The game was hard to scale up unlike most massed infantry games because you only needed a small crew. It was hard to find an incentive to buy more models unless you actually liked the design of the models themselves which i think a lot of people actually bought them for.
There was also a problem with having a no points system which was highly narrative based. Its too easy to blur into an RPG style game. The models in the narrative changed a lot, (i.e losing an arm and it becoming cyborg) but the miniatures weren't designed for change, so the only option was to continually convert them. But what happens if you want to revert back to my old human arm? it was just too much hassle. Theres almost no need for miniatures at all these changes could be easily written down on paper like an RPG, which equates to less sales for GW and a dead system.
At the time magnets werent common in wargaming like they are today and a plastic kit combined with magnetisation might be the solution.
40k doesn't have any of these problems highlighted above so its a much better alternative for the gamer and for the producer GW.
