What a wonderful idea. No doubt the civil service will shoot it down by claiming that they are totally inefficient and undeserving of the extra funds. The only thing I can say is that they haven't had to deal with both private and public sector.
Apparatchiks always have their own myths that have little to do with the whole of things.
You seem to be saying that the only use for the bank is regulatory. To do these things, it is absolutely vital that the Bank remain at arms length from political influence. Government, like all borrowers, must be subject to market tests. Down here we tend to equate the feeling of this with Corporate Welfare. The marketplace is really such a nebulous thought that it is difficult to define without resorting to a fantastic mythology about why people buy products and why they do not.