Cytocycle,
Yes, of course that can happen. But I'd have to say that that's just poor room/speaker match. In that price range, one can afford the right speaker for the room, or even to build the right room for the speaker. He's already paid for bass -- of extraordinarily high quality and for huge $. To add a sub to an already full range speaker, diddling with crossovers, "reinforcing" what's not working right, is throwing money and compromise at a problem that should be addressed at its root.
Anyway, just saying "away from walls" won't explain why he lacks bass. Of course imaging is best away from walls, and $50k Wilsons are built to have great bass where they image best (I have to assume). So either his speakers are set up not just away from walls but in a particularly poor spot for bass -- in which case either move 'em to somewhere else away from walls, or they really are irremediably mismatched with the room -- or the problem is the amp/speaker combo, as Gajgmusic suggests (that's my bet).