Because it's interesting. If "X" is 1000 lines of code and has cost $20k in bounties, and "Y" is 1 000 000 lines of code and has also cost $20k in bounties, it's interesting to see that feature X has relatively more high profile bugs when it probably does much less.

I wouldn't say that it's a moot point in every context. The metric we'd get here would amount to "given that this developer made a loc change, what is the monetary risk involved".

Developers that are high on this metric might want to allow down and think twice next time they commit.

Or not. Metrics are likely not very useful in general.

It’s a valid measure of the amount of code. 10 bugs in 100k LOC speaks of a very different quality than 10 bugs in 1k LOC.

It's the same as the idea of per-capita normalization.