I'm sorry, as sweet as this post may seem, I have to disagree on MANY points.
Judging from reading this entire post, it appears to me that you care nothing for the enrichment of a betta's life and only for their appearance. As per these selected quotes:
Because of these abnormally long fins that can be really heavy and delicate they are kept in small containers with no water movement....as cruel as some may think this is......this is needed to maintain the long flowing fins.
Most males are placed in a small container by the time they are 2 months of age-this is to encourage fin growth and often the reason we want a Betta...the long fins.
Plus many other instances of just "wanting pretty fins" throughout the article.
Also your "famous" quote of:
To be a good keeper of fish you must first be a good keeper of water and understand how they interact.
As a chemist, I have to wholeheartedly disagree about your stance on 1 gallon or 2 gallon amounts of water being "good enough". It is good enough and plenty for an experienced aquarist or an experienced breeder, but almost impossible for a beginner.
If I were to pour a bottle of poison into a koi pond versus the same bottle of poison into the Atlantic ocean, which do you think would die first? If anything, the Atlantic ocean would just laugh in my face.
Most experienced aquarists recommend LARGER tanks for beginners because of the ease of care. One slip up in a water change or too much food or overstocking will not be a major problem that will kill your fish instantly. Larger tanks, due to their volume in size, tend to dilute the problem so a beginner can easily remedy the problem once it arises. However if this is done in a smaller tank, casualties can be VERY quick and VERY high due to the small volume of water and frequent water changes.
HOW many people in the disease thread have less than 5 gallon tanks? Quite a few, because it is difficult to keep water safe/sanitary/whatever in smaller, quickly changing conditions.
In response to the betta keeping side of tank sizes, I'm not asking people to spend an exorbitant amount of money to buy some sort of 1000 gallon tank with all the latest whizbangs. A good starter size for a betta owner would be 5 gallons with or without a filter. Not only is it a more enriching environment for your betta, but it will give you a chance to learn additional things about fish keeping, such as cycling your tank (with a filter). Having your betta in some random 1 Gallon is like having some sort of high needs plant. Just change the water once a day and walk away.
As for the neurotic behaviour and other behavioural problems with betta in larger tanks, I personally think it comes down to two things:
1) If they were bred and held into jars since birth, that's what they're used to and comfortable with -- purely because they don't know any better. It's like randomly shoving a homeless person into a mansion, how do you think they will react? Some will go BERSERK and run around the house in joy, some will probably lose their minds and some will probably still live in their hobo-ish ways ad camp out in the kitchen or something.
2) Temperament of your betta: My female, Meilin does not give a darn where she is held, either 3 inches of water or 1000000 gallons. Mali on the other hand, I had to release him from quarantine early because he hated his one gallon, and looked like he was dying every few minutes. He's in a 2.5 sharing with Skittles (it's more 2 now, I moved the divider a bit) and he's full of UNBOUNDING JOY~
Skittles arrived to my home having wrecked his tail on the flight. He's in the other half of a 5 gallon and is currently building his first bubble nest, even to the point of digging up some of his baby plants to use as scaffolding. Seems pretty happy to me. He's a Halfmoon Doubletail and he moves like a dancer.
Having torn fins doesn't mean your fish is going to be super unhappy, unless of course it is fin rot or some disease. Having "pretty fins" is not all I care about in a betta. I would rather keep the ugliest betta in the world with the most shredded fins possible HAPPY in a nice tank they can ENJOY; instead of keeping a gorgeous fish on a 1 gallon pedestal in hopes it will never rip it's pretty pretty fins.
The main message here should be that you build your OWN personal experience with your fish. Do you want to know WHY there are so many stories of people who have 6 year old bettas in tiny bowls? Or WHY our pampered fish die? and more importantly VICE VERSA?