The problem is that most banks in the US are incredibly predatory, especially toward low income customers. Banks love to provide small amount short term loans (

The problem is that most banks in the US are incredibly predatory, especially toward low income customers. Banks love to provide small amount short term loans (honoring NSF funds) at usurious rates. Instead of bouncing a transaction that would overdraw an account by, say, one solitary dollar banks will let it go through then hit the account holder with a $30 NSF fee (which works out to something like 4000% APR or so). For poor people a bank account can look like a huge risk, which can introduce massive expenses in a moment's notice with the slightest mismanagement (or external emergency). Unfortunately, it's unlikely that this situation will change any time soon in the US, it's just too profitable for the banks and the government is too much in their pocket to actually want to fix the problem.