The BoC was created by the will of the people to be, just as it continues to be, a bank (to the banks). Of course it is going to raise and lower its interest rates, just like every other bank. That's what banks do. There was no need to seize power because the public explicitly wanted this bank to exist and for it to function as such.

It is told that the public does not want taxes to be raised. Why would those same people then give power to the BoC to raise taxes? The wanted a bank. They do not want higher taxes.