Economically it makes greater sense to run AC Trains, which even if run in losses in non-festive times, it will easily recover it's loses in peak times & be profitable, just like 3 star hotels. While some non-AC trains never become profitable in any season.
As ALD Doranto having Sleeper coaches was replaced by Humsafar, the railways introduced Sleeper only so that people do NOT complain about dissappearnce of Sleeper coaches during conversion. The no of sleeper coaches are limited to 4 & it's likely in no other Route of HS, sleeper will be introduced.