That seems way worse than the cups! If one betta gets sick he can infect all the others. Maybe then the store might care :/it always surprises me how LFS handle their bettas. I went to one a couple weeks ago (i just happened to walk by it and recognized that name as one of the better ones in the city) and walked in and saw their betta in divided tanks...no heater and not filter. Im talking about a 10 gallon with 20 bettas!!!!! It was divided into 10 slots and then those slots were cut in half and you could walk around the tank to you could see all the bettas. They had two of these stacked on top of each other and maybe like two rows of tanks like this. the water also looked horrible and the bettas were all sick/had major fin rot. When I alerted the store to them they said it was better then cups....
And those poor bettas with the bubblers, they really don't appreciate that at all, especially in such a small space