> These days if your chosen language doesn't have things like strong typing, interfaces, good debugging tools, a good compiler, etc, then you should definitely be asking yourself if it's the right tool for the job.
All of these things existed long before Ruby on Rails gained in popularity. Unless the popularity of Rails, Python, PHP, and Javascript was all just collective insanity, dynamic languages do offer benefits in some circumstances over languages with stronger type guarantees. Certainly not in every situation, but enough that it doesn't make sense to dismiss them out of hand.
All of these things existed long before Ruby on Rails gained in popularity. Unless the popularity of Rails, Python, PHP, and Javascript was all just collective insanity, dynamic languages do offer benefits in some circumstances over languages with stronger type guarantees. Certainly not in every situation, but enough that it doesn't make sense to dismiss them out of hand.