They had the blockers, go back and watch the play. Dillon moved to the left and blocked nobody at all and the linebacker came right thru the gap between Meyers and the RG and was ready to Rock Rodgers as soon as he was throwing. why change the play? How do you know Watson wasn't just to take safety out of there and 2 guys working deeper from left to right weren't the intended targets of the play? They should have been able to block it, they should not have had to change anything. It was 3rd and 10.
Even if he could have stepped in and drove the ball more, it could have been completed rather than his altered motion knowing he was getting blown up leaving the ball hang a bit again and Joseph was able to get over there.
And yes, Cousins should throw it deeper, Rodgers should throw it shorter. But who was shorter in a pattern? Tonyan 4 yards behind the LOS? I wouldn't bet on him gaining 14 yards after the catch if you spotted him 13.5 yards head start.