The full story is more complicated. The USPS is in an unattractive position of being supposedly independent of the taxpayer's money, yet any major operating issues are at the whim of Congress. Predictably, it goes like this:
USPS: "Volume is down, we need to raise prices."
Congress: "Nope, sorry"
USPS: "Uhm, ok. We'll have to cut Saturday delivery then..."
Congress: "No can do, sorry"
USPS: "Well I guess we have to close a bunch of post offices at least"
Every member of Congress in unison: "Sounds great, but not in my district"
etc...
I'm a big fan of the USPS -- I've found them to be more reliable than UPS and FedEx by far and they're amazingly inexpensive to boot. They know what they need to do to fix themselves, but sadly it seems to take a crisis before Congress will get out of the way and just let them do it.