That is certainly the status quo; I would ask, however, whether it is desirable. I think the system should provide more incentive for thoughtful comments, or at least some sort of disincentive for shotgun-style submissions. It is difficult to build karma by posting lots of comments; you have to put the effort into generating good content to get karma. The same should ideally be true for submissions; the difficulty, of course, is that since the content of submissions is generated by someone other than the submitter, simply posting lots of them /will/ eventually result in a karma-boosting hit.
We had a similar problem on our social network where users abstained from giving karma to thoughtful comments. Consequently, we coded an algo to add "+0.1 karma" to every user that gave another person "+1 karma". That was enough to take care of the problem.
