I was talking to my cyberpunk loving, DS9 suggesting friend again last night and he told me Voyager can be a hard watch if you care about consistent characters. He said the Captain seems to have a new personality every week. Sometimes she's all about the rules, sometimes she says damn the rules. Sometimes she's very encouraging, sometimes she's cold and harsh. From what he described, and from what you're describing, it sounds like either writers are being rotated in and out and don't understand the characters or the producers solicit scripts and then try to mold them to fit the show. I hate to compare and contrast westerns again (but hey, I'll stick with what I know I guess), I have a theory that the people in charge of the shows would often just buy scripts and then re-write them a bit to fit the characters and scenery of a show. A lot of the times plots would be so simplistic and stereotypical that anyone could easily take place in The Rifleman or Gunsmoke or Laramie without much adjusting.
Voyager is fucking terrible. Tupac the jive-ass Vulcan and Chipotle the Space Navajo. Rick Berman is the fucking worst. In many cases, it's the personality of the showrunner. Gene Roddenberry was a serial sexual harasser and his wife was always on set (Nurse Chapel, the Computer, Troi's mom). he was bad enough that when he offered Michelle Forbes her own show (DS9) she quit rather than work with him again. But as bad as Roddenberry was around women, apparently men did better. Berman, on the other hand, drove away anybody of any real talent and ran the franchise into the ground. Roddenberry had a great group of writers around him but there was a hell of a diaspora when he died. Rene Echevarria left. Naren Shankar left. Ron Moore left. They were pretty much left with Brannon Braga and DC Fontana.