[sargun]

Deadline based scheduling actually lets you do super clever things like "time-shifting" -- you have 10 jobs, that each take 10 seconds, and the deadline is 300 seconds out -- you can fit them in between other jobs. In addition, if you know the requirement of the job in terms of computational needs, you can determine really efficient collocation patterns.

IMHO, the problem is that it's really hard for people to think in terms of "I want my job that takes 10 CPU seconds to be done in 300 wall clock seconds". In turn, what batch processing frameworks do, is they can estimate these things, and figure out where to place work. You can also do stuff like deny requests if there isn't capacity (because you know all the scheduled work for the next quanta).