They clearly rely on people not comparing the market. I refinanced my mortgage away from CBA at the start of the year - got an interest rate 0.52% lower - saving me about $200 a month... If people woke up, they'd be toast (or actually need to be competitive).
Don't get me wrong but so what! This is true across virtually all industries, business are in business to make money funnily enough. The comment about competitiveness is true of supermarkets, car companies, telcos, retail outlets, wine retailers. in fact I can't really think of an industry it's not true about. And yes, if people woke up they'd be out of business. But of course we don't. But realistically I'd have to suggest the answer does lie in us doing exactly that, if I was in business why would I seriously look to cut my own margins if I don't have to, businesses are not charities.