We had the highest rated QB, WR with the most TDs, and RB with the most yards last season. That was created for exactly the reason you described. It still wasn't enough to get us more than 1 playoff win because the defense couldn't slow down a strong passing attack.
If there was no cap we would have just signed Murray, but in the a resource restricted environment where every dollar and pick spent on offense is less spent on defense we must make choices.
We are losing because of poor defense and have been for some time. We needed the money to spend on Hardy and the picks to fortify defense. With a stronger defense we won't have to have an 1800 yard RB to win.
Our team was good last year because of the run game period. Before the draft we added Hardy, got Lee back and now have a 100% Demarcus Lawrence. We have focused soley on defense and completely ignored the running game in the the draft.
We know for a fact that a solid running game makes us successful. What we don't know is will a potential great defense and scrub RB's make us better?
I prefer to go with what we KNOW works.
This season will now be a mystery. Will Romo be able to be as successful as he was last year? I seriously doubt it.
We certainly needed to improve the defense but we shouldn't have neglected the running game altogether. That will have bad consequences. Keep in mind DMF played in only 1 full season since joining the league in 2008.