SakashiroOn-foot pew-pew is optional. It adds gameplay options without taking anything away
Well, yes and no. It's true that the existence of a dodgy FPS within E:D doesn't directly affect any of the other gameplay options, but the time spent developing it could (and IMO should) have been spent developing something else instead.
So in that sense, on-foot pew-pew did take something away, we just don't know what it might have been.