If saves drop, then duration of said sleep effects also need to drop, like in half. Sleeping skills have a lot more going for them than just the ability to cast mals on sleeping victims. Personally, I'd rather land a sleep skill that lasts a few ticks and have the opponents sanc/protective/flight wear off rather than a shorter duration sleep just to make it easier for a blind.
While I could possibly agree that there is no need for it to affect saves, I don't think that the 32 spells example is a valid counter argument.
I can't count how many times I landed a sleep on my last necro just to run out of mana or run out of sleep timer without landing as much as a blind or curse on my sleeping opponent.
I had the same issue with a necromancer. I would land sleep and I maybe get one mal off going through about 1k mana. I would have to catch ticks so I was able to acid blast when slept wore off.
Yeah even with +1 mal and +1 spell I failed 18 blind attempts on a sleeping person just the other day. I did manage to get curse, but that took about 10.