Why would you be _more_ averse to sharing a bathroom if you're low income? I think it's more about American germophobia or new members of the middle class feeling that sharing bathrooms is beneath them now that they've made it.

In most places being poor doesn't mean you live in squalor, it just means you have less money. You are still doing your best to keep your place clean etc.

And obviously your neighbours won't be strangers for long.