I agree with you and even with the Watkins trade not representing a tank move - on paper at least. However when your new GM gets rid of the best receiver on the team who has looked healthy and ready to commit during preseason- this move comes off as a tank move and not a "win now" move.
No matter how you look at it, rightly or wrongly, the Watkins trade sends a signal that many fans interpret as a rebuild move (and probably players as well). It is the psychological aspect that hits home, not the analytics side of the deal. Bean F'd up IMHO, big time.