I personally know several successful professional women who have a policy of refusing to belong to any women-only groups. Their reason is that in their experience such groups are populated by people seeking reassurance. The result is that they offer the "support" of lowered expectations. Which won't help you succeed. One also pointed out to me that if a group of men were to form a men's only business club, that would…
If you are a member of a disadvantaged group, you often do not have the ability to identify as a professional first and a group member second. That is the effect of being disadvantaged. Other people will make your life seem primarily about being a group member. Think about dealing with sexist/sexually-charged comments, racial tension at the office. Even if you want to just be a professional, other people will get in…
Short, fat, scrawny, aging, young, poor, immigrant, religious, atheist, nose-picker.
Maybe identifying as a card carrying member of a "disadvantaged" group isn't the healthiest outlook to have.