He doesn't play a position of "need" right now, that is very true.
But the people complaining that they didn't like the move - not because of the compensation part, but because it was already a position of strength - are off base. Coming into last season, Parker had shown a lack of focus and strong practice habits and Stills didn't have a great first year here (although in my eyes the writing was on the walls that he was going to breakout). Adam Gase, the new coach, offensive minded, wanted to get HIS players. So the position wasn't a strength YET.
Ultimately, like someone else mentioned, why are we still crying about spilled milk? Move on, we cannot change the poor compensation given up to get the player, all we can do is hope he pans out. Life goes on guys.