Programmers already know the DSL for every problem: English (or their native tongue). If they're writing programs for a specific domain without knowing the language of the domain, they have problems that won't be solved by using programming terms they already know.

How many people have learned what MVC means from Rails? Or the term "routing" in the context of a webapp?

One caveat I'll give: the DSL must be well-conceived. Writing a DSL that is dissimilar to both the underlying language and the domain vernacular is obviously horrible.