I'd like to point on the idea of question as a knowledge resource.
It has come to my knowledge that understanding a subject, especially Physics, requires experience with as many questions as possible.
Reading many solutions of expert members of the Physics site may indeed help many students to understand Physics better.
Note that each person may contribute its own point of view and technique for solving a problem.
Though the policy that I experienced on this site actually discourages questions as such:
Many of my questions have 0 (zero) votes, therefore I received a warning that alerts me from asking more questions (which would probably get 0 votes, due to their 'homework' classification).
By changing the policy and gaining questions, students will be able to understand physics merely by reading Q&A on SE!
An answer to "dmckee" which is relevant for everyone:
Indeed, essentially, you are correct! I think so too: A student must make an effort to solve a question - this is exactly what I do for each homework question that I receive.
Though what happens when you're stuck on a question for 2 hours? 4 hours? Gave it another try in the following day? Tried every possible way that you can think of?
Eventually there's a deadline for every exercise, thus time is priceless - therefore a solution is needful.