Should one remove questions that are "pointless" since the problem is much simpler than one originally thought?
If it has been answered, the question should not be deleted out of respect for the answerers. (I think the poster can't delete questions with upvoted answers, even if s/he wants to.) Maybe the poster can explain with a comment that s/he has later realized that the question is much simpler than first thought.
But if it has no replies, I think there is no problem with the question being deleted.