What they did:
They drafted Blake Bortles.
I don’t think I have to elaborate any more than that. Bortles is a pick machine that has held back the Jaguars for the last three years and looks to be on his way out.
In this day and age, any QB that has a chance to be a decent starter in the NFL gets their 5th year option picked up because it is so much cheaper than market price. However, the Jaguars decided not to do that and that tell just about the whole story.
What they should have done:
They should have done what the Tennessee Titans have done in recent years. Build up the offensive line and a strong running game to support any QB that you get.
Sure, you may have to go through some growing pains but as a GM, if you are going to join your legacy to a QB you better be sure he has the weapons and supporting cast to exceed immediately. If not, you are just hoping that he is transcendent *cough* Mariota *cough* and can exceed in less than ideal situations.
Aside from that they had all the options that the Houston Texans did in Mack, Donald, OBJ, Evans, etc.