"Perverse incentives" isn't a LW catchphrase. It's a term from economics, used to describe situations where external changes in the incentive structure around some good you want to maximize actually end up maximizing something else at its expense. This often happens when the thing you wanted to maximize is hard to quantify or has a lot of prerequisites, making it easier to encourage things by proxy -- which sometimes works, but can also distort markets. Goodhart's law is a special case. I'd assumed this was a ubiquitous enough concept that I wouldn't have to explain it; my mistake.
In this case, we've got an incentive (karma) and a goal to maximize (insightful results, which require both a question and a promising answer to it). In my experience, which you evidently disagree with, judging the fruitfulness of questions (other than the trivial or obviously flawed) is difficult without putting effort into analyzing them: effort which is unproductive if expended on a dead-end question. Also in my experience, questions are cheap if you're already closely familiar with the source material, which most of the people posting in the MoR threads probably are. If I'm right about both of these points, valuing insightful-sounding questions on par with insightful-sounding answers creates a karma disincentive to spend time in analysis of open questions (you could spend the same time writing up new questions and be rewarded more), and a proportionally lower number of results.
There are a number of ways this could fail in practice: the question or answer space might be saturated, or people's inclinations in this area might be insensitive to karma (in which cases no amount of incentives either way would help). One of the premises could be wrong. But as marginal reasoning, it's sound.
This is all reasoning that should have been made explicit in your comment. Your objection has good thoughts going into it but I had no way of knowing that from your previous comment. I knew that "perverse incentives" was an economic catchphrase but thought you were just referencing it without reason because you made no attempt to describe why the perverse incentives would arise and why the LessWrong commenters would have a difficult time distinguishing intelligent questions from dumb questions. I thought you were treating the economic catchphrase...
I'm worried that LW doesn't have enough good contrarians and skeptics, people who disagree with us or like to find fault in every idea they see, but do so in a way that is often right and can change our minds when they are. I fear that when contrarians/skeptics join us but aren't "good enough", we tend to drive them away instead of improving them.
For example, I know a couple of people who occasionally had interesting ideas that were contrary to the local LW consensus, but were (or appeared to be) too confident in their ideas, both good and bad. Both people ended up being repeatedly downvoted and left our community a few months after they arrived. This must have happened more often than I have noticed (partly evidenced by the large number of comments/posts now marked as written by [deleted], sometimes with whole threads written entirely by deleted accounts). I feel that this is a waste that we should try to prevent (or at least think about how we might). So here are some ideas: