A thousand reasons, mainly becuase of reliability, excellent 4wd system with strong gearbox, immecable build quality, and they're resistance to corrosion
I'd say styling and reputation has a lot to do with it, with respect to the integrale comparison mentioned above, if they didn't have wide arches and look aggressive it'd just be a HF turbo which look shite.
Maybe also why 3drs and escos are popular and saphs arent.
I would actually prefer a Saph over a 3dr. But for some reason a Saph must be RWD in my opinion.
Obviously if i hit the jackpot i'd have a collection similar to the bonkers one, but id still love a grey saph.