Hmm, you make a fair point here. I agree that it is annoying for this list to constantly change while you're trying writing a question. The less visual "noise" on the screen, the better. This is exactly why I don't use Google Instant, a point I've made here several times in the past. So in contrast to what seems to be the general opinion, I upvoted your question.
But the problem is (and the point that several of the commenters are trying to make) is that duplicate questions have become a real pervasive problem. Lots of users (and not just newbies) are re-asking questions that have already been asked and received good answers in the past. Rather than duplicating these questions all over the place, we prefer that they be consolidated into a central location where the answers are easier to find. Hans points out that, given the site's enormous success, nearly 2 million questions have already been asked, and that makes it rather unlikely (statistically speaking) that your question will really be original.
This feature is the best way we've come up with so far to get people to re-consider posting duplicate questions. If you have a better idea, I suspect that the team would be all ears. But if your position is just to simply eliminate it altogether, well, that's a no-can-do because we want people to stop and consider the existing questions first. We want people to notice this.
In order for this to be a real feature-request, you need to propose a workable alternative, one that respects the original intention of limiting or controlling the number of duplicates while still (preferably) not being so annoying. I don't have any better ideas; do you?