I guess they do this to avoid people buying a cheaper transit ticket when their end destination is Doha maybe...? Although you'd think anyone flying paid F would be exempted!
When I had a 24-hour unplanned stopover (due to a missed connection) they actually pulled my luggage out of the system at my request and delivered it to the hotel a few hours later - very impressive service ^ - so maybe if you ask when you get to Doha they might be more flexible (but please don't take my word for it!!).