I also utterly don't understand why anyone would want to program in dynamic languages and lose the static type system. I mistype stuff all the time, and I really like the fact that my compiler will tell me I made a dumb mistake rather than finding out later during testing, or worse, via customer support.
I think what may have happened is that developers and tools got much better: developers got much better at designing and testing robust dynamic code (through working with server-side languages like Groovy and Ruby) and IDEs (I'm talking about Eclipse, NetBeans and IntelliJ) got much better at working with and debugging dynamic code. Overall this means that typos are less than they used to be and are much less likely to make it into customer hands.
The other reason is something that Warren touched on: