Vacuums exist. Nearly frictionless planes and more or less perfectly rigid bodies actually exist. There is nothing wrong with abstraction based on objective reality. Claiming that one is about to declare how economies ought to work is not a abstraction based on a preexisting reality. It is attempting to impose one's own subjective needs wants and desires on reality.

Partial vacuums exist. Somewhat frictionless planes, somewhat rigid bodies exist.

I don't see any difference between the idealizing in either case.

Spherical cow is not "how science is done". It is a joke. Jokes rely on reversing expectations, going counter to reality, for the surprise element. How science is actually done is you begin with the intent to describe the real world and from there you use whatever tools, intellectual or actual, at your disposal in order to accomplish your goal.

Really? I always thought it was a veiled criticism of abstraction gone wrong - sterile abstractions, abstractions which can't then be linked back to the real world.

That's religion, not science.

If you say so.