I once went to a members-only hackerspace that was very open and equitable, at least in theory. To join, you had to get a recommendation from another member and support from one more. They held regular open days and were very welcoming but definitely had an established subculture that didn't include much diversity. Joining really meant being the friend of a member or possibly a friend of a friend. If you were an outsider, you'd really need to show them you were already a part of their sub-culture before they'd consider you. Openness to diversity really meant openness to conforming to an existing culture before joining.
Diversity and inclusion is an extremely hard thing to get right or even to agree on what "right" means. I don't think anybody would agree that diversity issues are fixed now and so it can't be "time to turn the conversation to this being OK". As I pointed out in my story above, lots of people can't even see that there is a present and persistent problem despite the good intentions around fixing it. That's exactly why we need to pay more attention to studies like this.
You seem keen to switch to a conversation about nature instead of having one about nurture/culture (there were a few historical arguments about race that took a similar approach). Perhaps these two are so intimately bound that it's not helpful to make observations about one in the abstract. Instead, should we not simply focus on those things we can change and try our best to ensure the inequalities of the past aren't reflected in the culture of today? It's not about some set of absolute outcomes, its about the absence of bias - an outcome I'd hope we were all on-board with.