It's nothing to do with any of this, interest rates are being kept low to subsidise private banking. It means they can make a profit lending to people/small business.
In the meantime it sucks liquidity out of savers/pensioners into the economy. Great if you are BP, shit if you are one of the pensioners who died last winter as a result. But who cares about them anyway?
Interest rates are being kept low to satisfy the banks (and their subsidiaries) multi-nationals...it is after all the banks that own your property if you have a mortgage on it. If you have an interest only mortgage you are almost a renter...