Pretty much agree with you, with the proviso that if what I have heard is correct, the recent re-leases of the 146s are significantly less than the Q400 lease costs (of course fuel is more), so the cost difference is negligible too.
I'm not suggesting that pax will choose to pay more for a jet (although some clearly do), but simply that, all other things being equal, they prefer the jet to the turboprop. Who wouldn't?
Try operating on a route with excess capacity, against Easy, using a Q400. It would be empty most of the time.
The point of the argument is the assertion by our loyal Q400 driver that the Q400 is as quick as the 146. It isn't. Does it matter? Not really.