"These paintings have zero artistic value" is quite an harsh judgement, especially when defining the "artistic value" is so subjective.

It's not like commissioned painting is a new thing, and it yielded some masterpieces. Bringing it to a broader audience can be beneficial for artists themselves.

I remember seeing an interview of an African artist who was telling the journalist that before she gained some fame in her country she was living in quite a precarious financial situation. I think there's definitely some merit to such a service if it might help some artists in similar situations, as by solidifying a source of income, they could then devote themselves to paint things they really want to paint.