Part of it is purely game theoretic. Once one person realizes it's a successful strategy to send more messages then their competition, their competition also h

Part of it is purely game theoretic. Once one person realizes it's a successful strategy to send more messages then their competition, their competition also has to send more messages. Arms race quickly ensues. And once you have such an arms race on one side, the other gender no longer has to even bother initiating conversations. Why did the arms race tip towards men competing and women getting it easy? Probably cultural norms. But once the arms race got started, there was no putting it back in the bag.