I can't tell you why they specifically won't accept section 8. If I were to hazard a guess, it's because section 8 is generally low income housing, and there are certain pain points that come with that when it's related to tenants, maintenance, etc.
I can tell you that I personally would not do section 8 if I were a landlord. The reason being is that the home has to be inspected once per year and meet the housing authority's standards. You could be on the hook for repairs that are 100% beyond a shadow of a doubt the tenant's fault, but in order for the rent to stay subsidized, the responsibility for the repair is on you as the homeowner.
Most housing authorities are a pain to deal with. I say this as a PM that used to deal with section 8 in AL.
I see why people like section 8 tenants and the program - guaranteed rent. Ultimately, it's your call whether or not to accept it, so if you want to, I would see if the housing authority has a recommendation for a PM. If anyone is going to know, it's them.