That is absolutely true, and for my type of travel a short flight time is worth something.
Booking the most direct flight on AY directly from AY (avoiding OTAs as discussed elsewhere) the price difference is 900€.
Now, this was just a random sample. QR's normal flight time (available at the same price point) is 16h30 outbound, 19h30 return, so then we are down to a 4-5 hours lost each way chosing QR. Is that worth 900€? Actually, no it isn't to me, especially knowing how good QR is. And for the regular joe?
Besides, on this particular route one must also count on a 8 hour delay on AY's outbound, so...