I recognize the current upper limit on questions helps to prevent spam, floods, and this sort of distraction. But after reading Matt N.'s post and some of his questions, I am thinking a more helpful idea would be a regressive-tax-style upper limit that's tied with a user. Matt N.'s questions show effort and are excellent. Maybe the upper limit could be inversely linked with reputation?
Many users in Matt N.'s meta question are pretty positive about his questions. It would be a big shame if tip-top questions have to be delayed because of a upper limit that caps good and bad askers equally. Again, I think the daily limit of 6 posts serves its purpose for starters and bad askers. But posts like https://math.meta.stackexchange.com/a/4807/79539 discouraging first-rate askers are less helpful than a top-notch question that can help others thinking hard too. It's wonderful that there are ways here to sort out the good and the bad. I just hope the upper limit can be improved to reflect this.
Update December 24th 2013. If I'm not mistaken, some people downvoted. I'd appreciate it if the people who downvoted could explain and disclose why. I'd appreciate hearing thoughts and opinions. In summary, the privilege system here should apply to the upper limit on questions as well. I trust good askers have earned the privilege to ask more.
Update May 11th 2014. Someone else suggested a similar idea on the English website.