Supposedly diesel can get fungus in it . Thankfully I never experienced that. I also never had need to drain off water from the fuel filter either. But thee things can happen. There are a variety of additive products you can buy.
But I've never had problems with gas either - use stabil if something is going to sit for awhile - always keep tanks full if something is going to sit around to avoid condensation.
The only fuel problems I've ever had was back in the day when you mixed oil and gas for 2 stroke motors. That stuff could not sit around and lost half it's energy value in just a few months.
I would not consider fuel issues as a deciding factor choosing between gas or diesel. If your diesel is sitting around, unused for such a long time that the fuel goes bad, then you have chosen poorly. For a diesel to pay, it has to be driven many miles.