If we feel that we want to keep track of instrumentally useful contributions to the community but also want karma to remain a more-or-less pure representation of the reception of a user's comments, then the obvious way to reflect that seems to be to create a metric other than karma to represent the former. This might also be a useful way of reflecting certain actions that have traditionally been rewarded by means of upvotes on comments bragging about them, like posting survey responses or donating to CFAR or MIRI. Granted, the development resources for this aren't likely to appear in the near term.

Elsewhere in these comments I've mentioned the XP metric that the Everything2 community created to fill a karma-like niche. It was after my time, but I'm told they ended up creating a "GP" metric (RPG metaphor, yes) that worked similarly to this.