This question already has an answer here:
Eliminate rules regarding question types. Asking for advice or opinion is sometimes the most valuable information one can receive - especially if a person is about to go down a long path that ultimately could be a Dead End.
I am wrestling with a sea change in some research I'm doing and it is impossible for me to choose a path because I am not experienced in many of them.
Only by asking experienced people, can I choose a path meaningfully.
However these kinds of questions are not allowed(!)
You risk becoming the "about.com" of the scientific community - a dubious honor at best.