I can't agree. Voyager had a ton of potential and some very likable characters, but it was never an excellent show. It consistently failed to exploit its unique premise and situation, all too often in favor of doing the kinds of shows that could have appeared on TNG. Bringing the Maquis aboard was pointless if they were immediately going to end up in uniform and -- with a rare few exceptions -- not behaving any differently from Starfleet officers. (Chakotay was especially ill-served here; turning from an angry battle commander into a virtual pacifist overnight. The longer the series ran, the harder it was to believe he'd ever been a rebel.) Putting them in the Delta Quadrant and isolating them from their homes and home society was pointless if they were always going to be a virtuous Starfleet ship and never be changed by their new situation -- see my earlier comments about "Alliances."
Well, yeah. But that was a problem from the very beginning. It didn't start in Season Four, or with Seven, or with Brannon Braga.
Voyager did have flaws in seasons 1-3 but no worse than other shows. The writers had that habit which they kept during the show to come up with something, like the stupid nine-year Ocampa lifespan and the one-child syndrome and then, when they realized that it didn't work, they just kept on going like "Ah never mind, the viewers won't notice". Another such example were the situation with the shuttles and torpedoes where it was stated from the beginning that Voyager had two shuttles and 38 photon torpedoes. Still, they started to waste them already in the first season, another example of "Ah never mind, the viewers won't notice". But the viewers did notice!
What they couild have done is to come up with some explanation about a Shuttle And Torpedo Building Team on board the ship. But the constant supply of torpedoes and shuttles despite the constant waste and destruction of those were never explained.
But as I see it, it got worse in seasons 4-7 when everyting was about Seven and the other characters, except Janeway and The Doctor were shoved in the background. Such a waste!
Everything was about Seven, her Borg knowledge, Borg technology and so on (and I'm not gonna go into the whole "sexy Seven and the catsuit now) and how Seven could fix antyhing, from the entire warp engine to Janeway's malfunctioning hair-dryer.
Then we had the TNG thing. They had the possibility to come up with new, exciting species and adventures and really use the characters they had. Instead it was like "Let's bring in the Borg. The viewers love the Borg. I mean, the Borg were finished as a scary villain already in TNG. They should have come up with something new, like Species 8472 or the Voth.
As for the Maquis, I must state that I'm happy that the writers didn't come up with the same scenario as it was in the horrible series Stargate Universe where there were a constant bickering between the Civilian faction and the Military faction. Chakotay's decision to join Janeway's crew was logic considering the fact that it was their only chance to come home and that 30 Maquis or so were too few to take over the ship.
However, it could have been done in a different way. B'Elanna was domesticated too soon. It should have taken at least 4-5 episodes before she became the perfect Starfleet Engineer considering her behavior in "Caretaker".