If you wake up at 4 am and have to get up at 6.30, taking a hit and being able to go back to bed instantly and wake up in a few hours is much more practical than taking a sleeping pill, waiting 30 min for it to kick in and then not being able 2 hours later because the half-life of sleeping pills is at least 6 hours (for ambien) to 8-12 (imovane and most benzos) to 20+ hours (quetiapine, mirtazapine).

So that's why