Something that must also be considered when talking about keeping an animal or bird in the house -- especially something like a chicken, which naturally wants to live as part of a flock -- is that they need a lot of time and affection. If you have a single chicken, you need to spend time with it. It needs care, affection, love, and lots and lots of time, or else it will become depressed and miserable.
Chickens are like people -- the ones that can be happy all alone, with little affection from others, are few and far in between.
I've kept birds indoors for somewhat long periods in order to treat wounds and illness. They got restless, anxious, and would sometimes just start screaming for no reason, raising the alarm for their flockmates. They were lonely, and wanted attention, and that's just the noise -- they also reeked terribly, even with regular bedding changes.
This was just for a few weeks -- maybe a month or two, at most, and I sometimes brought in other chickens or let them outside to let them spend time with fellow birds.
You may have the space, equipment, and patience to take care of a gregarious bird such as a chicken indoors, but do you have the time? Hours each day spent playing with it, giving it the love and attention that it needs? If not, then it would be cruel to keep such a bird, as it would be lonely and miserable.
Even if you do have all of those resources and all of that time, keep in mind that you are not a chicken. You cannot talk to your pet chicken like another chicken can. Even with love and affection, your chicken may still become lonely and want another bird of its own kind to live with. There will always be a language and communication barrier between you and your bird.
If you are going to be stubborn and absolutely insist on keeping a chicken indoors, make sure that you have all of the proper equipment, and get at least two chickens. Bantam breeds are in general very small, and some bantams are tiny enough that you could probably fit two of them in a space that would hold one standard-sized bird.