@BlingLoving
"man says there's no inequality in the workplace and women aren't discriminated against etc. I point out that there are still more men called John as CEO in FTSE 250 or whatever, than there are women. I ask them to consider if this is just coincidence? Often, they still don't think it's about inequality/discrimination, but the first step is getting them to realise that there is a problem here."
You have a logical fallacy there, and that maybe why you are failing to get your point across. You have made an assumption that because there are more CEO's called John than there are women there must be therefore discrimination. You may be right about the discrimination, but that statement on it's own doesn't establish that in any way. It's circular reasoning unfortunately and needs more.
Maybe there is discrimination, and maybe there is enough of it that that accounts for the discrepancy. However there are other reasons that could account for it, like for example the male greater variance hypothesis. Maybe women make different life choices, and fewer women for whatever reason do not pursue life trajectories that would land them in a CEO's chair. Maybe little girls are socialised differently to little boys, and the problem lies much further upstream in women's lives. Perhaps it's a combination of ALL those factors, plus more that haven't occurred to me.
Now I know it might be tempting to read all that and see that as my inferring that discrimination doesn't exist, or that I'm minimising it far from it. I entirely accept sexist and bigoted people exist and I'm not opposed to the idea that some of those individuals may gatekeep women out of positions of power in corporate structures I am sure it happens. However I make no statement or claim that is or is not the primary cause of the disparities you bring up.
The reason I bring it up, is that it's incredibly important that you diagnose the correct cause of a problem, otherwise you end up spending energy trying to solve the wrong problem, and sometimes the cure is worse than the disease. If it turned out that women's choices was the biggest factor, enforcing choices on women would be too much of an infringement on their individual liberties, as you would have to make one hell of a dictatorial intervention to correct for that.
I'll end on a positive note though, fortune 500 companies that have a higher representation of women on the boards of directors tend to outperform those that don't, and if you find there are financial incentives over the time the market will correct for that by itself: www.thebalance.com/do-companies-with-female-executives-perform-better-4586443
Companies that don't have a more diverse board will be replaced with those that do in these circumstances, and inevitably you'll start to see more female CEOs as part of that equation.