This is an ok point, but the thing is, asking good questions involves already having some knowledge of the topic, which the user often doesn't have. If he googles the topic, he's gonna find it, refining the search and googling some more will maybe answer the question, and he's not gonna post it here. Some users are terribly lazy at googling. I often answer some questions by simply googling it by keywords, and yanking/pasting the first results.
So, I'll say, let them ask the questions in the form they wish. Questions will be modifies, refined and rewritten if necessary, and in the end we will have a good answer on the topic. Duplicate ones can easily be deleted (and usually are).
Answer to lothar since comments are too short:
Yes, of course it is. But, as I tried to point out, a new user will maybe not know it is a bad question. Because from his point of view (doesn't know) it is a valid question. And it is really.
From yours or mine, naturally, it is a bad/boring/repetitive question, 'cause we've seen it so many times before. That is a way of learning. To be a teacher one has to be patient.
Now, as you probably guess, this can be taken to the extreme. Trolls arise. So the question is "how to stop users from continuously asking bad question, which everyone can see make no sense?". Should something like, "question closed for LAZY USER reason - user cannot post another for 24h" be implemented (where LAZY USER would be a category where the answer to your question appears in the upper block while you're writing the question).