Well good, you go do what you want, Nancy. Meanwhile, my betta is perfectly healthy and happy in its so-called "glass cube."
Yes, I know where Bettas come from and what their natural environment is. But, its a natural and free environment-- not some glass cube.
You ARE aware that their "natural and free" environment is:
1. Often about the size of the glass cube. We're talking rice paddies that dry up into small puddles for half of the year.
2. Fraught with constant danger from the elements.
Bettas are also perfectly adapted to live in small environments. They get much of their oxygen not through their gills but from the water's surface.
You know what? I would never keep a goldfish in a bowl, even a large bowl -- for the simple reason that goldfish are fast-moving fish that use a lot of oxygen and need a lot of space. A goldfish bowl is entirely inappropriate -- yet you see this often, and even ads in aquarium magazines (usually advertising fish food) will feature goldfish in bowls.
Like I said, I would not recommend having any other fish species other than a betta in this small environment -- certainly not the danios (another fish that is fast-moving and needs swimming space) that companies like Aquababies usually put in them. My betta, on the other hand, is quite fine, thank you very much.
Regarding your choice of cohabitants for the betta, all I can say is that you are VERY lucky that your betta has not bothered your tetras and smaller fish. Oh, wait....you said it was a FEMALE betta. Well, that's not the same thing. Females are entirely less aggressive than the ornamental males that are usually what one buys when they purchase a betta. I, too, have seen tanks full of female bettas, twenty or thirty of them in one tank, all living peacefully among themselves and with other fish. Try doing that with twenty or thirty male bettas sometime. You'll have a bloodbath.
Even with a female, though, you are lucky one or more of your small tetras didn't end up as a snack. I once introduced a male betta into a 33-gallon tank that had mostly smaller tetras in it, and various other smaller fish. The betta ate some of the tetras and terrorized the rest before I pulled him out of there into another tank. So like you said....what's best for mankind isn't always what is best for the animals! Choose your "community" fish carefully.
I might add that having a gourami, even a dwarf one, in a 2-gallon tank is a much more tortorous practice than having a betta in a 2-gallon tank. Gouramis need space! The MINIMUM tank size for a dwarf gourami is 5 gallons, no smaller. Even more if your gourami isn't a dwarf.
And having a ghost shrimp in a little 2-gallon tank along with a predatory gourami?? Now that is torture for the shrimp, no doubt! That poor shrimp must be in constant fear for its life, especially in that small of an environment. If you had, say, a 30-gallon tank with the same animals and plenty of hiding caves and plants and things for the shrimp, and a lot of space in the tank so that the gourami isn't always in the shrimp's vicinity, then fine. But in a 2-gallon tank? That poor shrimp must be constantly stressed.
Another poster here mentioned that she has two bettas separated by glass partitions in a single tank. Unless the partitions are opaque, this is much more stressful to the fish than any smaller "cube" would be.
You also can't equate keeping bettas in smaller environments with keeping cats and dogs in kennels. Just as I would never keep a goldfish in a bowl, I would never keep a cat or dog in a small cage. They are intelligent, active creatures that need a lot of room to roam, and especially in the case of a dog, need the love and touch of either another animal, or a human. Keeping such animals in small cages IS torture to them. And it is not even remotely equivalent to the betta situation, whose needs are much, much simpler, and which is highly physically adapted especially for smaller environments.
My betta is going on 2 years, which is old for a betta, and he certainly does not look "depressed" or any worse for wear. So, do what you want. And I'll continue doing what I'm doing, because it works.