The strict definition of sexism is a mindset, and the only way to reliably determine that mindset is to have a mind-reading device. That means that almost every time we evaluate sexism, we use a heuristic, and choosing which heuristics to apply is necessarily subjective. For example, I find most of the sexism controversies do not have clear indicators of sexism, but I acknowledge that I applied my own opinion to determine those, and opinions can differ.
Since the strict definition of sexism is difficult to apply, it's also possible to use an operative definition and still remain objective. If we could agree to a set of heuristics, a set of measurable actions through which we can objectively determine that something is "sexism", then we could use that to make our judgement calls. However, I don't see such a standard proposed and agreed upon - in fact, the reason the issue is so controversial is that it seems there is very little "standard" about sexism that we agree on, and opinions about it have a lot of variance. I think it's normal for HN users to then express skepticism and criticize an ad-hoc application of rules to slap a label on someone when we can't agree on what that label means.
This is why I was looking for an objective standard to replace the dictionary definition of the word, which HN users agreed upon and then failed to apply when "SV culture" was put under a microscope.
EDIT: reduced repetition and improved wording.
