There is also the scenario where someone may not be able to open a bank account due to an extremely bad credit history, or not being able to meet minimum balance requirements (or have to incur relatively heavy 'service fees' to maintain an account with a low balance). The current mainstream alternative is money transfer services that charge a hefty percentage for transfers.
Most banks in Europe can't refuse to open a basic account by law. They aren't obliges to offer any credit (or even debit) services, but a basic bank account is supplied (in some cases, only way to get money from/to the government is to use a bank transfer)
To extend on that, having a bank account as a citizen is mandatory in France (and as such banks cannot stop you from opening one, although they don't have to provide any other services)
>> "There is also the scenario where someone may not be able to open a bank account due to an extremely bad credit history, or not being able to meet minimum balance requirements (or have to incur relatively heavy 'service fees' to maintain an account with a low balance)."
Might be another cultural difference. In the UK I can open a bank regardless of credit, there is no minimum balance or service fees unless I go negative into an un-arranged overdraft.
http://money.cnn.com/2012/09/12/pf/fdic-bank-accounts/