This isn't a judgement one way or another; I think your point is pretty valid. I'm just curious - have you read either of the books in question, or is this a more philosophical thing?
I've decided that I'll read the book where a character is resurrected, just so I can speak directly to it. However, I won't be picking up any further books that have the resurrected characters in them. They're well written to be sure but I have no interest in reading about immortals for whom death is a minor setback. At least in TSFS and TVH there was a period of time where Spock had to recover. Janeway basically came back and stepped right back into her old position. She might as well have been away on shore leave for all the lingering effects coming back from the dead had on her.
Data's a special case, being an android and all but it's still annoying. Now that he's metged with Soong, someone who took steps to avoid his own death, you'd think he'd be working on a way to keep a back up of his hardware and software, just in case.
He has other priorities first, but yeah.
In general, I think I'd have agreed with all of this before I read these two books but... hm. Let me see if this makes sense.
IF these were only book series, and there wasn't any obvious difference in importance between the TV show people and the novel-original people, I think I wouldn't have any objection to these two stories at all. They both make complete internal sense (which I wouldn't have ever thought possible with Janeway, but Beyer is just brilliant).
KNOWING that the TV characters and novel characters are different, it's irritating that I know the original character deaths are permanent but that TV characters almost certainly won't die and, if they do, they'll come back eventually. But that's external to the logic of the stories themselves, which track surprisingly well.
Does that make any sense? I feel like my only objection here is meta-fictional, but the novels themselves kick ass.