Could've been passable if they'd used someone like Saavik or Carol Marcus, or someone else of lesser consequence, but I agree it wasn't really a worthwhile effort
As I said, every
character has their fans. You
might believe Saavik or Carol are of "no consequence", but starting "Relics" with the off-screen death
of Saavik would have totally derailed the episode for Saavik appreciators.
(Of course, the arrival of Scotty derailed the Dyson Sphere. Even when a TNG novel investigated the Dyson Sphere, it was kinda derailed by a completely solid Starfleet vessel being casually hollowed out by its Horta crew.)
I am reminded of my own minor outrage when Garrovick, a particular favourite of mine, whom I'd used in fanfic, was announced as having just been killed in the movie-era novel, "Home is the Hunter". I still enjoyed the book, but what an awful way to start a story: using a known character as an offscreen redshirt death. With little followup, other than Kirk's moodiness.
At least Tasha's onscreen death had a heartfelt payoff with her funeral and eulogy.
By the way, the "Relics" novelization does
introduce us to Ensign Franklin, who has straw-yellow hair, and the book gives some other nice bonus scenes (including another scene of a holographic reunion for Scotty with his old bridge crew, which would have been included in the episode if time and money had allowed).