That's what happened in high finance. It was a big part of Ellen Pao's complaint in her lawsuit against Kliner Perkins.

I can see the history as proceeding like this: finance (and similar industries) used to have a Mad Men style sexist office culture. Then PC rules and HR regulations moved in to make the office a neutral ground. Then the power brokers moved the serious networking old boys' club to the 'after dark' part.

I can't say the goal of this was to exclude women from power all along, but that's the effect of it.