You may want to consider how your second sentence reads. It seems to imply that minority speakers would not be part of the desired lineup to begin with, and that they could only possibly be included "just for the sake of diversity".
Anyway, it's not about saying "gee, we better pick an Indian or two to meet our quota." It's about including minorities in the pool to be considered in the first place. That few or none were chosen indicates that that probably wasn't the case.
And this isn't about calling people out as big fat racists. Hardly anyone believes, in their heart of hearts, that people unlike them are inferior. But we all have unconscious biases like that[0], and many folks are starting to demand that people account for that in their decisions.
[0] Plenty of people are great at lying to themselves about it, too. Search for the phrase "I'm not racist, but" on Twitter sometime.
That still doesn't answer the question. Your response seems to suggest, as did Luigi's, that the organizers should have made a conscious effort to include women and minorities on the panel. The question is, why?
Because they evidently were unable to make an unconscious effort?
This is why I (sadly) consider myself a feminist -- we're still far away from equal opportunity -- where making an effort to overcome cultural bias in the form of sexism isn't needed. The number of commenters here and on the linked article that assume that a selection that includes only white males, clearly must be the correct one filled with all the most qualified speakers from England illustrates this point.
I'm not really supporting the idea of shutting down the conference over this -- I do see why someone might have raised the issue on Twitter. I don't quite see how it could (reasonably) go from there to cancellation of the event.
This sounds a lot like a tempest in a teapot to me -- the real issue seems to be that their sponsors were spineless twats. But then again, that seems to be what you get for trusting the invisible hand to help you get things done.
The question that needs answering is not how they should have gone about selecting a diverse group of speakers, but if they should have. What's the value of diversity on a technical panel?
I'm not saying that diversity has no value, or that the speakers were the best possible speakers who just happened to be white men. I'm saying that, if you're going to claim that the speakers should be diverse, you need to justify that claim. Is it better to have diversity in speakers than the most technical accumen, or is it your argument that the best group of speakers will likely be diverse? What about when they're not? Why is diversity important?
Now, for what it's worth, I believe the best group of speakers probably would be diverse, but only by virtue of the racial and gender composition of the set of experts, not because diversity itself has any significant value in this case. That the selected speakers were white men may be evidence of a suboptimal selection process, or it may be simply a statistical anomaly. What it isn't, is a problem in its own right.
I think the assumption is that given that other successful conferences have had speakers that were good (technically), that were non white/male, that if such speakers had been considered for this conference, the organisers wouldn't have ended up with a lineup of 100% white & male speakers.
You're right though that we have no real evidence for this, this is just a natural assumption to make given the evidence we do have (the lineup).
As a poster said above me, this could have possibly been mitigated by publishing who they considered and possibly even selected that were non-white/male and couldn't make it. (this would give us some of the evidence you mention).
It was not my intention to come across that way. The person I was replying to took the position that diversity should be a huge focus when choosing the speakers.
I don't know whether or not minorities were considered in the first place, but if they were and none were chosen we would still be sitting in exactly the same position. I have no doubt that there are loads of great minority Ruby developers, but that doesn't necessarily mean they live in London, are available on the given day or are interested in conducting a presentation.
I don't think it's entirely implausible that the hosts chose their speakers fairly and ended up with this selection.
Anyway, it's not about saying "gee, we better pick an Indian or two to meet our quota." It's about including minorities in the pool to be considered in the first place. That few or none were chosen indicates that that probably wasn't the case.
And this isn't about calling people out as big fat racists. Hardly anyone believes, in their heart of hearts, that people unlike them are inferior. But we all have unconscious biases like that[0], and many folks are starting to demand that people account for that in their decisions.
[0] Plenty of people are great at lying to themselves about it, too. Search for the phrase "I'm not racist, but" on Twitter sometime.