I love that people want to blame what happened on non-binary and trans people as if it's their fault that all these cis men are liars. I'm seeing far too many comments about blaming this on "gender ideology". Victim-blaming at its finest.
This policy change was a huge departure from the original mission back in the 1990s, which was to have a conference by and for female computer scientists, who every day have to endure the effects of working in a field that is very heavily male-dominated.
I hope that this year's influx of insolent men calling themselves 'non-binary' has reminded the organizers of the extent to which males will dominate given the opportunity, and why their change of policy last year was so absurd and harmful to women. By trying to be more 'inclusive', the end result was female exclusion.
That said, there has been a lot of ideological pressure to center 'gender identity' in recent years, so I can understand why the organizers may have felt the need to go along with this. But redefining 'woman' to be some unfalsifiable inner abstract feeling of femininity doesn't work in reality, given that this is not the basis on which women are discriminated against in tech or anywhere else.
Non-binary people are also under-represented in tech and the change was an attempt to deal with a situation that is itself non-binary, despite what people may pretend. Most men are allies. Just because some took advantage of the situation doesn't put the blame on the people who were taken advantage of.
Also, your generalizations are not helpful for this situation. Do better.
Your 'gender identity' is literally the words you say or the box you tick when asked what your 'gender identity' is. A policy that welcomes 'non-binary people' is a policy that welcomes any man who says he's 'non-binary'.
Women at the event were saying they were literally barged out the way and hurt by men pushing past them. Everyone is well aware of who the men are in this situation, but policies that prioritize declarations of 'gender identity' over reality have the effect of pressuring women to ignore their natural instincts, lower their personal boundaries, sit silently in their discomfort, and basically just be nice and accepting.
I'm glad to see the pushback against the hordes of disrespectful men taking advantage of the situation, but it will all be for nothing unless the organizers fix their policy to keep these men out in future. Women deserve better.