[xyrouter]

The lack of static typing does not explain why there are so many companies using Python, Ruby and Perl but very few using Lisp. If the lack of static typing was the real cause of the lack of popularity of Lisp then Python, Ruby and Perl also would have been unpopular.

[lenkite]

Because each of these dynamic languages offered one feature which was/is the best in the world at the time.

Python today has the best numeric computing libraries (numpy and sisters) which make it the most widely adopted language for scientific computing, ML, etc.

Ruby had Rails - the web framework that trail-blazed convention over configuration and rapid productivity and was considered leading just a few years ago. Ruby's popularity has waned since then as performance and scalability has become far more critical than plain productivity alone.

Perl had the best regex features and reporting facilities fifteen+ years ago. It has lost its crown and is rapidly declining since Perl 6 took forever and is basically a completely different language.

[Volt]

Python enjoyed a whole lot of popularity before the ML trend took off. If that's the best thing going for it, I don't think it really answers the question.

[cafard]

Perl also has CPAN. It had mind-share, as Python seems to have now.