It's just a good cooking skill to know how to do a basic white sauce. I learned fairly early on, and it's been a base for a lot of things. It's an excellent base for a curry sauce if all you have are onions and curry powder. Not very authentic, perhaps, but certainly tasty.
Making a white sauce is not difficult. The main thing the cook needs to do is slow down, read the recipe through and stay with the sauce on the stove. You can't walk away and leave it. That is a recipe for disaster. Just not a good idea.