They still are, they're still references in durability/quality for motorcycles as well (together with the other Japanese manufacturers).

“Sure, your rocket’s reusable, but can it go 300k miles on the original engine?”

300k miles is only about 12 low earth orbits, so easily achievable by a second stage booster (though it’s going to be coasting for most of it). Not so easy for a booster though.

Really once the rocket is in space, the joke kinda falls apart; frictionless vacuum and all that.

Awaiting the rocket engine equivalent of the K20.