Excellent point, Chief.
Keeping a bad coach is almost as bad as giving up too soon on a good coach.
But there are three counter arguments I would offer.
1. In the absence of hiring an obviously superior coach (Payton), I would maintain offensive continuity for our still developing young QB is a huge consideration in favor of keeping Bradley another year. If offensive continuity enables Bortles to make better, faster reads and better decisions overall, that will lead to fewer turnovers, fewer sacks, more consistency, that will inevitably result in more wins, which is what you want from the team.
2. I maintain there is still an argument that the current approach Caldwell took with the team is working. No, the W-L-T record has not been good. But the talent level overall is increasing. He proceeded under the idea it would take longer to build the offense. It's taken two years, and clearly it isn't fully where we want it to be, but it is beyond dispute the nucleus of an explosive and contending offense is there with Bortles, AR15, Hurns, and Thomas Thomas has already made a Pro Bowl. AR15 is making his first this year. Bortles was 2nd in the league in TDs. Hurns had 10 TDs and 1000 yards on his own. What we haven't seen is a requisite investment of high draft picks on the defensive side of the ball. I think with another year in the offense as described above, with better talent overall on the defense, combined this team will win more games, which is, again, the whole point. Yes, we've only had 3 coaches since 2003 (4 if you count Mel Tucker), and ALL have been hamstrung by a pronounced lack of talent. That has finally turned around on offense. Give it a chance to turn it around on defense as well. At the very least, with something close to a complete team, we will know once and for all if the coaching is good or not. With something close to a complete team, we will have a better idea how to proceed if we decide Bradley isn't the guy.
3. As I indicated before, firing the current coach, assuming that is the preferred solution, is actually only half of the solution. The other part is to find a suitable replacement. That is far from guaranteed. What would be worse than sticking with Bradley if he were not the guy is dumping Bradley, sacrificing the development of Bortles and the rest of the offense, never developing the defense and still ultimately ending up with a substandard coach. If Bradley isn't the guy and he is fired at some point next year, at least Bortles would have seen enough defenses, enough fronts, enough coverages to be able to transition into almost any offense, and have enough of a frame of reference to be good for the new coach.
Worst to 1st. Curse Reversed!