"I'm not sure the Italians or Japanese would necessarily agree with you there."
Not that I care very much what their opinion is, but what is the experience you are referring to?
I don't know of any air force that has had the air refueling experience that the USAF has. If the KC-135 had proven deficient, it would have been discarded quickly - certainly during the cold war - and in more recent times despite their aging airframes and relatively austere avionics, have once again proven their worth.
Now, I have no disrespect at all for any country, like the UK, Australia and even Korea that has made a different choice. In fact I have no disrespect for the MRTT/KC30 , either. I wish the best to them, our dear allies and friends.