I was approached recently at a technology conference by a male attendee asking:
Are these groups, like RailsGirls, really helping or are they just causing gender differences to be more apparent thus creating a divide?
This is when another male attendee chimed in:
Yes! Those groups are just another example of reverse sexism.
Just to clarify the definition of "reverse sexism":
Reverse discrimination is discrimination...in favor of members of a minority or historically disadvantaged group. ...This discrimination may seek to redress social inequalities where minority groups have been denied access to the same privileges of the majority group. In such cases it is intended to remove discrimination that minority groups may already face.
It was apparent that this question originated from conversations with his male peers. I felt glad that he trusted me well enough to open up and ask this question to a woman in the field.
But I also felt dissapointed that questions like these still exist. This question was asked by a leader in the community. This person could have made a true impact on whether women and minorities felt included in his group.
I answered the question as well as I could. Explaining the difference that I've personally seen in the community after the introduction of RailsGirls, a group encouraging women to learn Ruby on Rails.

Before RailsGirls was formed in Atlanta, I was often the only woman to attend the Ruby Users Group (aside from a couple of recruiters who showed up to give their pitch then quickly exit). The only reason I attended was to accompany my husband. I could always rely on the excuse of, "Oh no, I'm just here with my husband, I don't know what any of this stuff means."
If I wanted to learn Ruby on Rails, I didn't feel that this was the place to do so. I certainly wouldn't have invited another woman to attend. Don't get me wrong! It was educational and the people were nice and completely non-discriminatory. I just wouldn't have felt comfortable raising my hand to ask my obviously newby question.
After RailsGirls had their first workshop in Atlanta, there was a rise in women attendees at the Ruby Users Group meetings. There was also a new place where women could go and feel comfortable learning.
I tried to explain to my male inquisitors that the Ruby Users Group, packed with at least 60+ men, was not a place where a woman could comfortably ask about an issue running a migration after directly editing their schema file. But I have seen this first hand at RailsGirls. And everyone nodded and exclaimed in agreement that, "Yes! We have all made this mistake before."

These minority groups are just trying to create a place of comfort for their attendees to learn. Sometimes that place of comfort is where everyone shares your skin color, education level, or gender.
All I know is that I've seen RailsGirls be a place of comfort for so many women. At RailsGirls, a code review will never be mistaken as a date. It encourages women to attend majority male attended events because they know their fellow "RailsGirls" will be there.
I'm not sure of the best way to express this to men in technology except to continue to talk about it. Attitudes won't be changed quickly, but I think more open discussions in our community can move us all towards a more inclusive culture.