I guess you could also somewhat argue, that programmers who have already potentially jumped (or diversified) from something that was more mainstream (PHP, Java,

I guess you could also somewhat argue, that programmers who have already potentially jumped (or diversified) from something that was more mainstream (PHP, Java, C# etc.) to Python/Ruby - are more prone to jump or at least try out new languages. Or more cynically they have a higher potential of being language hipsters :)