This is really, really idealistic. Most people do not have the flexibility to just up and quit, and most people in this situation do not have the influence to "

This is really, really idealistic. Most people do not have the flexibility to just up and quit, and most people in this situation do not have the influence to "destroy" a salesperson without getting fired or at least censured. It sounds like either you've never been in a situation like this or you should back up a bit and take it in at a higher level; you're missing the forest for the trees. You're assuming the client contact you have even knows "the process that brought [them] here," which they often don't, and that they are going to be interested in discussing it with you, which they often aren't, among other things. This conversation is also more often, in my experience, one step removed: Rarely have I seen this actually happen with a technical implementation person in the room. More typically it's a salesperson and a project manager, and you just get marching orders after the fact, which may or may not make sense depending on the PM's ability and willingness to make sense of the client's requirements.