I thought you were done. You promised. It's a frigging pedogical point. Many teachers of relativity feel that it causes more confusion than artificially preserving Newtonian expressions buys you. That's all. It makes the distinction between Newtonian mechanics and relativistic mechanics more explicit. It's the same damned theory. If you think this is 'dumbing down' you should probably take your flabbergastion elsewhere. It's just a change in the emphasis of notation.You just stated 'where is the issue'. All the traditional formulas now have to be changed by multiplying by gamma.
And I wasn't sarcastic. Just flabbergasted at the way the physics community has dumbed-down.