Although the answer to this questionthis question turned out to be about text versus maths mode, it could so easily have been about something specific to MathJaX.
It is probably inevitable that we'll get questions about TeX spin-offs, should we:
- Tolerate them - there won't be that many
- Tolerate them, but leave notes to the effect of "Probably not the best site for this question"
- Actively discourage them