This is simply personal preference; I have no problem reading Ruby code. Perhaps this is because I spent a very, very long time with Perl, but other Ruby hackers seem to feel the same way. On the contrary, I don't much care for looking at Python code, because half of it seems to consist of the word 'self'.
So, 'readability' in this case isn't a very valid argument, because anyone who codes in language X is going to find X to be highly readable.
Well, yeah. That's why I said it was my experience.
I think the point is, I code in Ruby and in Perl, and my opinion is that neither language is particularly readable or maintainable. Meanwhile, I have less experience with Python than either Perl or Ruby, yet I find it to be a consistently readable language.
Those are all opinions, but they're informed opinions (and I'm not simply advocating for the language with which I am most familiar).
So, 'readability' in this case isn't a very valid argument, because anyone who codes in language X is going to find X to be highly readable.