You have to choose between all the same kind of stuff with PHP too. The position was "I'm using PHP, and I can't switch to another language because I am afraid

You have to choose between all the same kind of stuff with PHP too. The position was "I'm using PHP, and I can't switch to another language because I am afraid I'll pick the wrong one". That position is silly, because anything you pick is guaranteed to be better than PHP. There's no "wrong" between python and ruby, they are for all intents and purposes the same. As for your specific case, writing your own framework in lua doesn't make ruby a wrong choice. You could have written your own framework in ruby too. Or perl, or python, or even one of those dreaded compiled languages.