So, in other words, you're saying it IS politics. Or is a bureacrat not a politician? And what law are you talking about, that says they have to put that number there? Or are you just assuming, and spewing your uneducated opinion, yet again?
That number is there for a reason. (As I previously stated) They are not forced to put it there.
Another reason it is there is so that some dumba$$, with or without an air gauge, doesn't blow the tire up by grossly overinflating it. Ya, it would take quite a bit more than the stamped on pressure to cause a tire to blow, but after 23 years in the business, I have seen some idiots give it a hell of a try. Like a 155/80R/13 tire aired up to 98 psi.
"That number has little relevance to proper use of the tire"? So, if "Max Pressure 40 psi" is stamped on the tire, it's ok to inflate it to 20 psi, or 80 psi? WRONG!
The relevance is simply this:
Rule of thumb. On a compact car, the pressure can be as low as 28 psi, or as high as the max pressure, when loaded. On a midsize car, the pressure can be as low as 32 psi, or as high as the max pressure, when loaded. On a full size car, the pressure can be as low as 36 psi, or as high as the max pressure, when loaded. Any deviation from these recommended pressures CAN cause a blowout and/or loss of performance and tire life. Period.
Got any 3's?