The Ravens and Chargers have the luxury of maybe "wasting" a pick on those two players, both teams were ultra succesful last season, and they have no glaring weaknesses to address.
We don't have that luxury, we haven't been drafting well and that has caught up to us, Saban to his credit drafted fairly well, Wanny well....err..
So with our 5th pick gone next year, we couldn't take the chance IMO, it is instructive to note that teams even lower down the totem poll passed on those players as well, and they have more needs then we do.