I don't mind change, but I also miss "in-series" books and don't understand why we can't get a mix of the two instead of only relaunch books.
I don't like the TOS 5 year mission stuff either. Getting something as good as Shocks of Adversity is rare, and I'd have traded that for another relaunch novel.
The impression I get is that for TNG/DSN/VOY/ENT/etc, post-series continuations are the books that sell the best, and that for TOS, Five-Year Mission books are the ones that sell the best -- and that between them all, TOS books set during the Five-Year Mission sell better than any others and help keep the Trek
line in general afloat.
So, heck, I don't mind putting up with six successful TOS novels where the Enterprise
meets a planet-of-the-week if they help subsidize a DSN or TNG Relaunch novel later on.