Actually, it was part of the original USB design spec that the plug connector always have the USB symbol on the same side (pins up), and that the port ALWAYS be CLEARLY marked with the USB symbol on the correct side of the port to demonstrate correct orientation. Also part of spec was that the plugs/ports be made to such tolerance of rigid enough materials that it really is not possible to plug it in upside-down without just jamming the fuck out of it like an imbecile. Corporate fuckwittery & cost-cutting is the reason those specifications became so fungible; no other excuse.
mnem
Of course, enginerding myopia fuckwittery is the reason that devolution was not anticipated and engineered out of the design.
Yup. Badly designed sockets exist on pretty much every USB hub or computer; I have sitting in front of me a device with multiple USB sockets, one of which is inverted with respect to the others - and no polarity indicators. If I can see the key inside the socket when making the connection, I'm OK; otherwise, the plug will fit either way but only fully seats in one position. Worse, some of them take enough force to seat properly that you really have to be careful when you can't see the orientation. Bad engineering, full stop.
The plug is also, as noted, exactly the right width to fit into more than one other type of socket, which is great when you have a partially hidden device and no polarity indicators. USB-C at least eliminates the polarization issue, though I'm very nervous about the long term survivability of that little male contact inside the socket.