I have asked Is remaining single helpful in mathematical career? today and it was put on hold as off-topic. While How hard should a mathematician work? is acceptable with many positive votes and favourites. I am not complaining about anything but just wondering what kinds of soft questions are considered suitable for math.stackexchange?
Whether a question is on topic does not depend on its tags. If it is primarily opinion-based, it should be closed on that basis; tags are irrelevant.
In every tag there are off-topic and on-topic questions: the fact that a question matches a tag description does not qualify it as on-topic.
The tag soft-question, as some others, was carried from MathOverflow because the first users of Math.SE came from MO. It predates Academia, Math Educators, and History of Math sites. Many of the good career-related questions within this tag are actually Academia questions (and should be asked there now). Many others are questions about teaching and learning mathematics, and belong on ME.SE. Some are about the history of mathematics. And others don't need this tag at all; adding it was sometimes a gesture on the part of the author similar to "excuse me for asking something so trivial".
What I'm getting at: soft-question is a tag that outlived its purpose. It should be removed.