that's the theory, but it's bullshit, and we've seen that over the last several years, as the central banks have caused a serious housing crisis in north america and pointlessly slowed down the economy while making no discernible effect on inflation. the central banks have made stupid decisions that have harmed the economy and harmed the citizens of the country over the medium to long term.
the basic point is that monetary theory is wrong. if we had a science of money that we could actually enforce independently of politics, this idea of independent bankers would make sense. however, there is no science of money, and the central bankers are not making better decisions that better affect people. they are in truth more often than not using out of date and demonstrably wrong formulas to make obviously bad choices, based on outdated and obsolete models, and they don't have a better science to use because there just isn't one. we're trained to look at them like scientists, but they're more like high priests asking oracles for direction. we have more than enough information at this point to make it clear that central banks are a dangerous, unstable and unsustainable way to run an economy. the central bankers are not experts in any meaningful sense, they're politicians like the rest of them, and they're making decisions that benefit a class of people insulated from the rule of law and that have legislated themselves above the rule of law, which is called investors, at the express expense of everybody else.
it's not entirely clear that trump should be taken seriously when he has argued for lower interest rates and it may just be the case that his recent hissy fit is entirely to do with not getting his own way.
but the evidence in front of us makes it abundantly clear that the idea that taking this out of the hands of politicians and putting it in hands of technocrats has not had and will not have the intended effect of putting experts in charge of something that politicians might screw up. over the last five years, the central banks have screwed up worse than any politician ever could and, crucially, they were completely insulated from any appropriate consequences when they did completely fuck up, as they clearly did. the data is clear that those rates should have never been raised in the first place. what's missing in the system and needs to be restored to bring back democratic accountability is a mechanism in which voters, taxpayers, workers and citizens can tell the bank "you fucked up, and i lost my house. fix the mistake you made.". otherwise, the future looks like unaccountable and technocratic rule by the high priest of the federal reserve enforcing the religion of monetary policy, and that future looks exceedingly bleak.