I liked the final season of Enterprise and I think that they totally succeeded in saving the show from a creative standpoint and even managed to do so in a way that didn't try to alienate anyone who enjoyed the earlier seasons. The problem was that it had lost too many viewers by that point and didn't have a good way to bring them back. Maybe if they'd done the Mirror Universe episode earlier or if they'd added Shran as a regular. Something big to entice the lapsed fans who loved Star Trek but were bored with the warmed over Voyager plots that Enterprise did during its first 2 seasons.
The final season of Enterprise to me, was sugar on a turd. I believe that had the final season writing staff developed the show, it would have been much different. Let's say, "set a show before Kirk" was the mandate. You put the Reeves Stevenses in charge of that, and they come up with something much better. They also would have compiled much better writers from the beginning, and the show would have done much better than Enterprise, which was a copy of a copy of a copy, developed and written by people that were clearly out of gas and unoriginal.
By the time the 4th season writers got to it, I feel they did as much as humanly possible with the hand they were dealt, and with the exception of a few episodes, notably the finale, improved the show as much as they could.
It would have been a completely different show had the 4th season staff had it from the get go.
As for Justice League, all things being equal, I tend to prefer Joss Whedon movies over Zack Snyder movies. But I think that Snyder movies have their place. And I certainly don't think that even the worst Snyder movie can be improved by making it less Snyder-y. The thing is, in many ways, Snyder is a very talented filmmaker. His visuals are among the best in the business and he's good at maintaining a dark aesthetic that I enjoy. Where his movies tend to get into trouble is right at their inception, when Snyder points himself in a very wrong direction and then keeps going. The result tends to be a beautiful mistake. What he needs is not for someone with a totally different style to try to remake his films after the fact. That just results in a watered down mess that pleases no one. What he needs is a good writing & producing partner who can point him in the right direction in the first place. He needs someone to, from the very beginning, gently explain to him that Watchmen is NOT about reveling in violence and Superman movies should be about HOPE first and foremost.
My issue with Snyder is that he tried to make the characters his rather than respect who the characters were. Snyder couldn't have butchered Superman more if he never heard of the character. If he is a talented filmmaker, then he should have known enough to write the characters in character. But his Superman was Batman with Superman abilities.
I think your last sentence nails it. How can you make a Superman movie where Superman doesn't inspire hope? And Batman v. Superman was a horrible idea. How much did he have to dumb down Superman to make Batman beat him? I don't care that Frank Miller wrote an overrated story 30 years ago that made Batman into the most powerful being in the universe. Batman fighting Superman is like an ant fighting a T-Rex. You can arm Batman with all the kryptonite that exists and Superman will win.
The man can move almost as fast as the Flash. Before Batman could even twitch a thumb, he would be disarmed. In that fight in Batman v. Superman, Superman could have ended the fight as soon as the kryptonite wore off. All he had to do was remove all of Batman's weapons, which he could have done easily.
Snyder fell for the "give Batman time to prepare" lunacy, not to mention the whole Martha debacle.
Snyder may be a good filmmaker, but he clearly was wrong for DC.