The big problem with DSLs is that they are not composable. Writing expressions in one DSL within expressions of another is often very tricky, if not impossible.

The big problem with DSLs is that they are not composable. Writing expressions in one DSL within expressions of another is often very tricky, if not impossible. DSLs also tend to be leaky abstractions. If I need to drop down a layer of abstraction in the middle of an expression of your DSL suddenly I have to understand all the mechanics of your DSL.