Yes, we stayed at WL one year during the July 4th week. There really aren't any good locations to view the fireworks. WL is surrounded by many tall trees which obscure the view. Even from the boat dock, you are not going to see all of the fireworks. The trees and scenery just get in the way.
If you stay there and don't want to go into a park, just hop a bus to the Poly, (it's the first stop), and view from there, or hop the monorail and view from the contemporary.