It has a 1-to-1 correlation, though: the faster you can generate code (which is the one quality under discussion), the more lines of code you can generate in a given unit of time, and vice versa. So I would argue we are talking about lines-of-code, just indirectly.

I don't see how one can hold "speed of code generation" as a good metric while, simultaneously, holding "number of lines generated in a unit of time" as a bad metric. And more worrisome, I'm not sure how one would reward one without rewarding the other creating a perverse incentive. But I'm open to be proven wrong.