I meant "not necessarily to program in". E.g. it's not going to be something you use all the time. The sad fact is that a lot of existing code and companies use fairly safe languages like C and Java, but simply knowing how to think about functional programming will help you out with all your programming, no matter the language.
I'm curious why you consider C to be safe but Haskell not. Seeing as C has no bounds checking on arrays, runtime type-checking, or garbage collection, I'm tempted to argue to the contrary.