Strong typing over the long term will always produce a more maintainable software product when used correctly. For many applications, you might not encounter enough complexity for it to matter strongly one way or another. Once you do finally encounter that application with 40 different entity types, 12 different business contexts that each of those can uniquely interact within, and hundreds of properties for each, you will be scrambling to find some way to bring order to your chaos.

Dynamic typing is useful if you are forced to develop software before you understand the business model or if you need to expose some DSL to your users. I normally view it as a short term option that is typically reached for when not enough actual engineering has occurred (in more complex systems). It's also mandatory for working within certain domains (i.e. the web). I think this last point is why so many seem to think its a perfectly acceptable way to carry on in any sense.