At the time the Postal Service was established the govt had to provide it as the private sector didn't even exist. Do we need it now.. probably not. Either way it wasn't a 'bet' but a service the govt provided. Solyndra is just a fucking waste of money.
I was merely pointing out the provision of postal service is in the Constitution, since you said the gov't should only provide those things that either the private sector can't do or that are Constitutionally mandated. From the above, it appears you don't actually know that the post office is in the Constitution. Not sure about that, as I've reread that reply a few times to try to figure it out, but right now I'd bet you don't, or didn't.
It's also an apples to nuts comparison. Businessmen get to "externalize" their inefficiencies, politicians do not.
You are correct sir.. at the time of my writing the post u quoted , I did not know (or forgot). However, they could still cut the shit out of it ie. deliveries 1 day a week, less offices etc. Do you see anything in the powers of Congress section that mandates or even allows for investment of tax revenues into private ventures? That was my point.