If they could buy back all the firms, resources etc that had been sold off to private enterprises (by various govs)and ran them like private enterprises do, just think how much less we'd be paying out or how much the government would get instead of lining the pockets of those investors who seem to have the cash to spare.
If the government could really run things as cost-effectively as the private sector does, then you might have a point. Unfortunately, this does not ever seem to have been borne out, historically. Most governments it seems can barely run themselves, let alone businesses! (Not that I agree with privatising the Fire Service, btw, because I don't).