I have a suggestion: after first creating an account, users could be redirected to the 'guidelines' page. That might help frame the tone of subsequent comments.
There are many fields (for example media, PR, some civil service positions) where communication is the primary skill being assessed - written in the CV & spoken in the interview. If you have a non-maths written component to your interview, you're being judged on your communication skills/literacy.
I agree there is often something else required too - but not always in a 'first' or 'graduate' position.