In fact it is. And can be useful. IF you have quality controls in place, so the code has a reasonable quality, the LOC will correlate with amount of functionality and/or complexity. Is a good metric? No. Can be used just like that to compare arbitrary code bases, absolutely no!

As a seasoned manager, I have an idea how long a feature should take, both in implementing effort and longness of code. I hace to know it, is my everyday work.