Isn't a conference for just Pythonistas considered segregation?

Definition of segregation for your convenience:

the action or state of setting someone or something apart from other people or things or being set apart

Indeed, a broad definition of the word would include this. I meant to imply that I was talking about segregation of groups which are often considered in genuine social conflict with one another, like gender, ethnicity, sexuality, religion, rich/poor, etc. Sure, there are "holy wars" between groups like Pythonistas and Rubyists, but I think most people agree that this doesn't reflect genuine social struggle.