You're right that we shouldn't care about some random statistic...but we should be interested enough in these random statistics to ask the question "Why is that happening?" I mean, if someone told me that 25% fewer men were going to choose to become doctors, that would make me wonder why. That's a pretty big shift regardless of gender or profession.
Personally, I don't think we're doing such a bang-up job in the IT field. Take the frequent reports of mass compromises. Take the latest DDoS by video cameras of all things. I think we should care that the best people to go into the field do, if they want to, absent any outside influence.
So, do I want to artificially nudge the stats so we have 50% male/50% female? No, not at all. Stuff like this should spur us to ask why it's happening, though, and if it's due to some outside influence (like we're systemically dissuading women in technology), then yes, we should do something about it.