Although that question is basic -- it is conceivable to me that many professionals might not know this. They might be trying to administer a unix box for the first time and are just confused by not having any numbers in there. I can see someone new typing man crontab, not knowing that the man pages have sections, see no asterisks and giving up. Therefore I make the personal decision not to move it.
The question also isn't terrible since the person bothered to use punctuation, the shift key, code tags etc...
The idea is that questions that are relevant to system administration and have straight forward answer to someone will likely be useful to others in the future even if they are basic. It hopefully will only ever be asked once and it becomes the canonical answer.
The famous question on stackoverflow relating to this for programmers is Joel's "How do I move the turtle in Logo?" and it is talked about in this stackoverflow meta post. In podcast 58, if I remember correctly, Joel is more for basic fundamental questions being okay to be asked once than Jeff was.
Ultimately the decision must be made by the community itself. Now that I am a moderator, I only cast a vote to move a question if I am very confidant that everyone will agree (hopefully get that right -- yell at me in meta if I don't). It takes five close votes to move the question and this is how the community can direct where the line is drawn. This system also makes the community flexible over time. As the question base grows more questions should get closed as duplicates. However, I think discussion of this on meta is a great idea as well.