Why do people think that Bettas are evil and need to be kept alone?

i have one male betta in each of my aquriums...they are alot happier in a large tank ....the first reason i think people think they should be in small bowls is that in stores there are all those 1-5 gallon tanks saying "great for betta" #2 reason is that when you go to a store selling them they are in those small containers so i guess people ume they only need a small tank #3 reason is after people see al that they tell others that bettas are easy to take care of cause they only need a small tank .most of which i bet dont even do the water change often or have a filter or any other thing the fishh would need to survive well...it is easier if they are in a large tank cause you dont have to change water as often and the fish will be more active , happy ,and healthy