There is an asymmetry here: long time users know far more about new users than vice versa. (And reputation is an imperfect proxy for this.) @Sycorax: yes, rep is supposed to convey this. But the problem is that you would need to understand the system at least to a degree, or read the help pages, to understand this aspect of reputation, and that many new users don't seem to do either.

Public Service Announcement Coupled With Shameless Self-Promotion: in view of the frequent questions about point forecast error/accuracy measures, I have heavily edited my answer to this question in the hope of having a canonical duplicate target.