>Debating how to fix it is important, but debating whether or not sexism actually exists trivializes the problem in a toxic way
You are walking into an extremely dangerous territory here. If reasonable people can disagree with you on the points you are not willing to debate (such as the widespread existence of sexism in tech[1]) or (worse) that you find morally wrong to debate then those reasonable people will not consider you reasonable - not only do you then lose any chance of changing their perspective, you will also create a schism in the community. This is what has happened in the US over guns, to the point where there is now no hope of reconciliation.
For example I could counter the few well published incident by pointing out that the media cherrypick a few stories and them run with them - what you see in the media is not an unbiased sample. A few stories from a large enough group does not mean that the group is especially sexist, it just means that it has a few assholes in it. We don't know whether the asshole procentage is higher or lower than in the general population and we don't know that if it is higher, whether there is some third-party variable (such as a general disregard for rules) common to both tech people and sexist assholes or whether the causality runs the other way (ie assholes are more likely to be tech guys because they don't work well with people).
Before we bring out the big guns and tear this community (which I highly value) apart, can we please have some independent, unbiased, studies - both as to the extend and effect of sexism and what causes it? Armed with this knowledge, we will be in a much better position to find out how, if at all, we should address this issue.
[1]: There is sexism in any sufficiently large group of people, independent of the field you gather the group from. What is more interesting is how large a percentage of the group is sexist.