In this particular context (large, professional groups), I think the idea is that there should be no sexual advances or presumption of sexual advances at these professional events.
> I've even met some that expect others to know they aren't showing any signals - and thus every sexual advance is unwelcome even if they say nothing about it being unwelcome.
The baseline assumption is that no one is sending signals in a professional context (even if some do, even if some do with malicious intent). There are graceful ways to initiate engagement in a non-professional context that opens the doors for appropriate signal sending. Even this must be handled carefully, since one person may be thinking “romance”, while the other is thinking “professional socialization”. This is especially true if one person is in a position of power (e.g., a VC in a start up community).
> I've even met some that expect others to know they aren't showing any signals - and thus every sexual advance is unwelcome even if they say nothing about it being unwelcome.
The baseline assumption is that no one is sending signals in a professional context (even if some do, even if some do with malicious intent). There are graceful ways to initiate engagement in a non-professional context that opens the doors for appropriate signal sending. Even this must be handled carefully, since one person may be thinking “romance”, while the other is thinking “professional socialization”. This is especially true if one person is in a position of power (e.g., a VC in a start up community).