Why do stores keep Betta fish in small containers?

From a marketing point of view, Betas might be kept in small bowls/mini-tanks in order to make them seem "easy" to manage and a simple, starter fish. Going into a pet store and seeing all the large tanks, requirements, etc can sometimes be overwhelming. Perhaps seeing the small tank makes a customer think "Hmm, this can't be too hard to take care of. I'll take it!". That being said, I think it downplays the level of care betas needs. I'm not saying they are high maintenance but they do have some maintenance. It's like the myth of the "goldfish bowl". Goldfish should not be kept in goldfish bowls.