Is there a difference between not creating a "safe, open, inclusive and intersectional" space and just not getting people of whatever minority group to show up due to some other reason (such as lack of interest)?
As a woman, I can tell you there are spaces that feel distinctly like an "old boys club" that are not AT ALL safe, open, and inclusive for women's involvement. And there are spaces where men inhabit that don't feel like an "old boys club", and as a woman I DO feel like I'm part of the group where both men and women can genuinely co-operate. Usually, though, it's been carved out specifically by women and where I don't get the sense that I'm a Token Female in the room.
Also, what is an acceptable number of minorities for an interest group? How is it measured?
Typically, the best ways are to seek out intersectional spaces that are already highly diverse. As a part of the Black Lives Matter movement, I saw myself as part of groups
initiated by white feminists that never reached out toward womanists or black feminists, and the result was a bunch of white women sitting at a table talking about what might be best for minority men and women in response to police brutality. Once I began seeking out groups initiated by black men and women and standing with them as an ally, the diversity was much more apparent when it came to addressing racial tensions in police brutality.
It's not like groups seek a quota or anything. It's the willingness to support minorities as they speak out on what is important to them. That takes the willingness to enter into
their space and to stand with them as an ally, but one has to be really careful not to enter into a space ready to "correct" their perspectives. A successful intersectional space gives people who normally are not heard by the public their voices and gives them respect for their perspective.