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'

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.