IMHO, IT IS NEVER USEFUL!!! It will lead to headaches down the path.
Some components may not be useful just because you don't use them or have an alternative way to do things(maybe better). Like dataset in VS IS NOT USEFUL = HAS AN ALTERNATIVE like LINQ. You can replace dataset with LINQ if needed and get rid of dataset once and for all. But that doesn't mean it is not useful. I still find it more comfortable even though I know LINQ simplifies things 100000 times.