I thought her novelization of Voyager: "Flashback" was great. She had to double the length of the story, so she added a really good Kes subplot and a Paris subplot, and she expanded on the ending in a way that made it much more about Janeway's character rather than the pure technobabble climax of the episode. So I'd say it treated the characters pretty well.
Given Carey's attitude, I don't think it's that surprising that Voyager
's tribute to TOS, featuring TOS characters, is the novelisation where she actually put in some effort. The other series' characters just happened to benefit from her elevation of TOS in this case.
That sounds like a pretty labored rationalization to fit new evidence into your pre-existing thesis. Couldn't it be that she actually liked Voyager
? You're forgetting that she did another VGR novel, Fire Ship
, which had nothing to do with TOS and is also well-regarded. (She also novelized Equinox
, but I don't think I ever read those.)