Well, what hampered them was the fact there was the Inquisitor table top game made by Games Workshop already, which actually did a perfect job of covering the Inquisitor story-style. Or it might be the other way around since Dan Abnett wrote the Eisenhorn/Ravenor series for the Inquisitor game.
But yeah, it's basically the trope of "We need to make something new and exciting, but the thing that happened before already did a good job of portraying it, so we have to just make do."
Which they did a good job, it's just that most people I hear who interact with it do it for the Space Marines, not the Inquisition. So the games weren't themselves failures, but I feel that they failed to convey what they were trying to do. If that makes sense.