OP (Jaguarmvp),
Thank you for taking the time to answer my questions and give more insight into your thinking. Unfortunately on this computer, I do not have the quote feature (and strangely I can't even copy and paste), but I will do what I can to answer your points accurately and intelligently.
1. I am glad you acknowledge the team lacked serious talent when Dave and Gus arrived thanks to Gene Smith. Their task in rebuilding this team was herculean. I think as far as talent acquisition goes, Caldwell has done a pretty good job replenishing the roster (more on this later). Regarding your Devil's advocacy about "drastic turnarounds happen[ing] all the time," usually, the drastic turnarounds that happen are not immediate turnarounds, and are usually the sum total of years of adding talent that finally comes together, or there are star caliber players already on the roster upon which a turnaround can reasonably be expected. Right now, only about three relatively recent examples of "drastic turnarounds" leap to mind: The 1999 St. Louis Rams, the 2013 Kansas City Chiefs, and last year's Texans. The 1999 Rams were the culmination of shrewd drafting/talent acquisition over at least a three year period prior to their breakthrough year. Between 1995 and 1999, the Rams got progressively worse, winning 7, 6, 5, and 4 games until winning the Super Bowl in 1999. An outside observer would think the team was headed in the wrong direction. However, during that time, the Rams added DE Kevin Carter (1995), RT Fred Miller (1996), LT Orlando Pace (1997), DE Grant Wistrom (1998), RB Robert Holcombe (1998), DE Leonard Little (1998), QB Kurt Warner (1998) and WR Az-Zahir Hakim (1998), and finally RB Marshall Faulk, WR Torry Holt, and CB Dre Bly. In addition, Isaac Bruce was on the roster in 1999, being added circa 1994. It's not as though Vermeil and company set the world on fire immediately upon their arrival. As demonstrated above, their wins were trending in the wrong direction. It took them a while to assemble all of those pieces and for them to learn what they had (remember, they traded for QB Trent Green while they had Kurt Warner; the plan was to start Trent Green until he hurt his knee) and develop sufficiently. While a drastic turnaround, it was far from an immediate turnaround.
The second example I listed is Kansas City, who finished 2-14 in 2012 and went to 11-5 in 2013. They changed coaches from Romeo Crennel (a better coordinator than HC) to Andy Reid, who is a fine HC. Certainly that played a role. However, the 6 Pro Bowl Caliber players already on the roster helped a lot in that regard (RB Jamaal Charles, LB Justin Houston, LB Derrick Johnson, LB Tamba Hali, and S Eric Berry. Reid came in and stabilized the QB position with Alex Smith. We both acknowledge, unfortunately, that neither Caldwell nor Bradley had that nucleus of talent at their disposal when they arrived. While 11-5 would be a lofty goal for this team, the evidence is clear that it was unrealistic for the team to follow this model of turnaround.
The final example of the drastic turnaround I listed were last year's Texans, who finished at 9-7 and just out of the playoffs after finishing 2-14 the year before. Their model follows the Chiefs example. There was already a lot of talent already on their roster: J.J. Watt, Andre Johnson, LT Duane Brown, LB Cushing, RB Arian Foster. The seemingly unprecedented meltdown at the QB position by Matt Schaub, who threw devastating pick 6 INTs in an incredible number of consecutive games which led to their collapse. Once they got some level of competence at the QB position in addition to the new coach, their turnaround was possible. While Bortles needs to elevate his game to elevate the team like the Texans did at their QB spot (and like the Chiefs did with Smith), without question, this turnaround is not applicable to the Jaguars situation.
2. The question regarding Bradley is fair. He may prove ultimately to be a better coordinator than Head coach. But he hasn't had the talent to give a fair evaluation on his coaching ability until now.
3. Then explain the Rams. If you examine their history, they were trending in the wrong direction. Under your rationale and looking solely at the records, they weren't adding any talent between 1995-and 1998. But clearly that wasn't the case. To extend this argument further, the 70s Steelers did not add talent between 1969-1971, but we know that wasn't the case with Bradshaw, Greene and Harris. The Cowboys of 1988-1990 didn't add any worthwhile talent because they all had losing records, but an examination of those drafts showed Irvin, Norton, Aikman, Johnston, Stepnoski and Emmitt Smith. You may ask why didn't that logic apply to Gene Smith? Because none of Gene Smith's first round picks really showed too much promise immediately, except for Justin Blackmon.
4. I think that can't be determined unless we know exactly how the season develops. I think if Bortles plays well and struggles with injuries (either to himself or his surrounding cast) and the team underachieves, I think it's too soon to pull the plug on Bortles Bradley or Caldwell. However, if all of the players are healthy and simply stink on ice, then maybe you look to reset. I don't think this last way is likely at all. I think if the team underachieves this year (less than 5 wins), injury will be the primary cause.
Worst to 1st. Curse Reversed!