When I was in college back in the early '60s we were taught to use metric for everything and that soon the whole country would. Out of college I found it a very hard sell - and eventually realized why.
Basically we've added some things like soda bottles that are metric, and most things stay as they always were. We can measure in millimeters if we want to or inches if we want to - usually we want inches. In weights, if it's smaller than 1/4 ounce we tend to shift to grams (our electronic scales switch back and forth at the touch of a button).
Highway signs no longer bother with metric and recent cookbooks have pretty much given up on metric. I get the sense that even in metric countries people are settling on cups and spoons.
But what's this business with Australia having a 4 teaspoon Tablespoon when it's three t to a T everywhere else in the world, including New Zealand? Somebody must've been kicked in the head by a kangaroo.