nobody is suggesting getting anything huge for them. a 1 gal tank is not massive, and could easily fit into a halls of residence room. but having said that, i have a small glass tank, 14x8x8 inch, this holds approx 3 gal, with a reasonable gap at the top. it easily fits on my desk next to my computer monitor. i only keep 1 betta in there, but it could easily be divided for 2.
in a glass that size his water should be checked much more frequently than weekly, weekly is recommended water change for a 1 gal tank, you can't see the ammonia building up in his water, but that doesn't mean its not there.
you completely ignore all the comments about keeping a cat in a carrier or a dog in a crate, but they are valid comments. even if you move him into a slightly larger tank occasionally does not make it ok. how would you feel if someone kept you locked in a cupboard for a week, but said its ok because you can come out into this 1 room for a week afterwards before you go back into the cupboard again, its fine! would that make you happy to go back into the cupboard?
most LFS say that bettas are fine in such tiny containers because they live in shallow rice paddies in the wild, but those rice paddies go on for miles and miles. they have plenty of room to swim about and exercise.
Also earlier in this post you asked how long bettas live? you have mentioned you have 2 bettas, but there are 3 shown in your pictures. can i assume that the other one died recently? how long had you had him? do you know what caused his death?
you are not going to win this arguement. NOBODY on this forum would condone keeping bettas in such cramped conditions as you have provided, people will continue to argue with you over it, until you either give in, and buy a bigger tank/s (

) or leave the forum (

which would be a shame as you would miss out on all the good advice)