I've always found it amusing that editorial writers want all kinds of taxes to pay for every 'necessary' service under the sun, but let the USPS even hint that ultra-cheap mailing rates for newspapers and magazines be raised a fraction of a cent, and you'd think that someone was trying to burn down the Constitution! Or at least the First Amendment, the only one that matters to them.
I once worked at the USPS and still have relatives and friends who work there. Some workers aren't worth 10K/yr and there's some who I think were worth more than 43K. The poor working hours probably should induce a little higher compensation than typical comparable jobs. The Cato article does have a little better "tone" than a lot of analysis of the USPS. Some of the stuff from people like James Bovard seems to confuse economic inefficiency with moral turpitude. Postal workers don't have to be falsely portrayed as worthless parasites to make a case for reform. There's a lot of good existing now within the USPS that should be salvaged in reform.