I can see, and agree with both sides of this statement. There are people on this site who put immense amounts of time and money into these fish, and all animals and just want to see them happy and healthy. Part of it is the way they are treated in pet stores, and the general misinformation of employees or blatant negligance. It boils blood...easily especially since people have this idea that fish are lesser than other pets like dogs, snakes, cats ect.
However, it's up to you the owner to decide what is right for you, and your fish. There is always going to be the most optimal condition for any pet, but as long as your fish is exhibiting healthy signs and seems happy I would say you're doing a good job.
As long as you are providing a reasonable place for your betta (1+ gallon) with good care, it will always be better off than the cup you bought it in
I honestly think some of the members are so severe is because not everyone keeping a betta, or looking at these forums is an adult, it's meant to discourage people, or children without the time or capibility to do some things mentioned (such as sororities, breeding, or community tanks).
as far as your sorority idea goes, I have had my males for a couple of months now, and I recently came into a 10 gallon, and wanted to make it a sorority. After reading extensively, and backing it with my previous aquarium experience (kept salt water, and freshwater tanks for 4 years). I decided to go for it. People have been nothing but receptive, and helpful when they see you want to do the best thing for your fish,and if you can reasonably provide for them they will reasonably respond just my two cents.
I guess what I'm saying is, I feel like I'm going crazy here XDD I want to start a sorority tank when I get an apartment of my own but I'm so afraid that I'll be "doing it wrong," no matter how much I research into it... I dunno, anyone else feel the same way?