The first time was after the great pilot episode. The pilot was, IMO, the best of all the Trek first episodes. Then it jumped the shark right into a pool of blandness. Part of the idea was there could be conflict between the Starfleet and Marquis characters but they seemed to all too quickly become a lovey-dovey crew. the most science fictional characters was Kes. But they copped out and never followed through with the great concept of a humanoid who's full lifespan is seven years. The showmakers didn't allow her to be much more than bland then they jumped the shark again and got rid of her because she was....bland!
They replaced her with Seven of Nine, who turned out to be a good character but they jumped the shark again by pretty much making it the 7 o' 9 show! And they relied too much on older concepts, The Borg and Q, because they couldn't seem to come up with new ones that catch on.
You know, I could go on but the problem was, IMO, fear of being different from what had come before, of being safe. It was like someone decided that ok, we've a female captain and some Marquis on the ship and they're all lost in space so we can write variations on the same themes in that different wrapping and we'll have something bold and different. Wasn't so. I don't know how much of the problem came from Berman or from Paramount but while I didn't hate the show by any means, I found it to be a huge bundle of unfufilled potential.
'A screaming comes across the sky. It has happened before, but there is nothing to compare it to now.'