It's very rare that such questions actually have an answer .e.g. something like
Why didn't Gandalf teleport Frodo and
the ring to Mount Doom
Can be answered with "there is no evidence that any being in Middle Earth has the power to teleport", however that isn't the actual answer. The correct answer is because it was not written that way.
I do not see how these questions help the site, they have no actual answer and can generate endless suppositions posted as answers.
Also, for each of these questions, there are endless variants, so if "Why didn't Gandalf or Frodo Fly to Mount Doom?" is allowed do we also allow
- Why didn't Legolas (who is very
strong & can run quickly and
silently) not run to Mordor with
Frodo?
- Why didn't Gandalf call Shadowfax and
carry Frodo into Mordor?
- Why didn't Saruman lock Gandalf in a
Dungeon?
- Why are Elves tall?
- Why are Dwarves short?
These kinds of questions can - validly - be applied to Sci Fi topics e.g. (I'm making this one up) "Why didn't Caprica have a space elevator?" You can discuss reasons (perhaps they couldn't fabricate materials strong enough, perhaps they had cheaper out-of-orbit options etc.) These answers then prompt questions like OK, so how strong do space elevator cables need to be? which can be researched, calculated etc.
However this doesn't work for magical realms.
I was initially surprised the community didn't just close these questions, and have tried to enter into the fun of it and provide some answers, but really I find them annoying and honestly think they're absolutely pointless
Either every opinion is an answer, or there are NO answers.
If there is no answer, then the question does not belong an a Stack Exchange site.
If every opinion is an answer, then again, the question does not belong on a Stack Eachange site.
P.S My "favourite" of these questions is How can the time variations be explained in the first three books of the 'The chronicles of Narnia'-saga?
Really dude? You want an in universe explanation for that? Really?