There is an argument floating around that there is a greater use of foodbanks because there are more food banks, and that people will take advantage - but you cannot just poll up at your local food bank in your Bentley and expect to be given a box full of food or what have you - It is a voucher based system, so you would need to find someone - a GP, a copper, unemployment office, to issue you with vouchers, which implies at least some degree of sceening for those seeking to take advantage.
I do not think we can dismiss the rise of food banks as being simply fuelled by blackguards gaming the system...