Frankly I don't know if Jackson knows how to throw well enough to make his WR's look quality. This season he has Flowers (First round pick), Bateman (First round pick) and Odell (First round pick) at WR (They also have Agholor who ironically is also a former first round pick). Oh and by the way he had Hollywood Brown (First round pick) who they traded away.
Sometimes you have to wonder if it's the WR's or the QB that is the problem. Or maybe it's the offense, which of course has always been tailored to what Jackson does best. It's sort of a chicken or the egg question. But the Ravens have certainly put resources into the position. Maybe they suck at picking players to use those resources on. Or maybe it's because Jackson isn't that good of a passer. From watching him, Jackson doesn't look like that good of a passer. His best throws are when guys are running wide open because the defense is terrified of his legs.