I have maintained mine and also have a Swiss one. I see the benefit of a US license as if we visit and rent a car we can always get less expensive rental insurance as a rider on my parents auto policy vs thru the car rental agency and to do that we need a valid DL.
Also any need for documents, like if you give birth abroad they sometimes ask for my US DL # or most recently we are getting additional life insurance policies and they need the DL #. However, we plan to eventually move back to the US.
I think you are doing a good thing renewing it -- less of a hassle than letting it expire and having to go to the DMV to get a new one issued.