Why do they have exposure compensation

[Cathus]

so if you set aperture & shutter in full manual mode you can still dial in exposure compensation with a Nikon?

In which case I agree with the OP, seems a pointless setting if you are making the decision about shutter & aperture anyway.

[chris-p]

Yes. You can still dial in exposure compensation.

I don't know how much use it really gets. I do know a couple of people who always have it set at -2/3 or so to try to make sure they don't clip highlights too much. Setting that via exposure compensation would certainly be easier than remembering to do it each time.

Otherwise, I don't see much point in it.