I'm more after looking for ways to get a qualitative feel for how big a deal the issues are that caused them to resign rather than how big an impact their resignation is. But I guess it seems the HN community has pigeon-holed me here and prevented me from getting much discussion about things. Maybe another day :-/
I think the reason you're taking fire is that your posts have questioned the sincerity and commitment of the Blums. Many people on HN would rather assume good intent, for two reasons.
First, because of their gravitas as prestigious researchers. (I'm actually a bit uncomfortable about that -- most people who experience gender discrimination haven't won Turing Awards, but we should still listen to them.)
Second, because sticking your neck out about gender issues guarantees a ferocious response and will make your life hell, so nobody does it whimsically. So what if they're not 35? Doing this at 75/80 is still incredibly unpleasant.
Like I said in my other post, I think we as members of the public do not have enough information to pass judgment. But if the Blums choose to say more, I hope we will all give them a fair hearing.