[davidw]

You'd have to ask the guy who wrote the code in the first place.

I think he saw "'best' compression" and stopped looking there.

[pmoriarty]

I didn't mean to ask why the defaults are defaults, but rather why anyone would use the defaults rather than settings more appropritate to their use case?

It's not like xz is unable to be lighter on memory, if that's what you want. It's an option setting away.

[davidw]

To clarify: you'd have to ask the guy who wrote our code.