I wouldn't even raise an eyebrow at this cake.
There's a lot of romance and glamour associated with the Titanic, and its story. The fact that so many people died tragically has almost become a side issue. I'm not suggesting that is OK, but it's a fact. The Titanic film is a Hollywood blockbuster but focuses on the romance, and the story of Kate Winslet and Leonardo di Caprio is what everyone talks about. It's a "romantic" film, not a horror movie - which really it should be bearing in mind the number of deaths!
**disclaimer - I've not seen Titanic film and don't ever intend to.
If anyone has sit and enjoyed the Titanic film then it's a bit hypocritical to criticise a cake which depicts the same theme.
And yes, at school it's taught as a subject which is fascinating rather than tragic. I can recall it very clearly. There was lots about the ship and how amazing it was, and how a series of unfortunate events led to the sinking. The deaths are very much glossed over, or only touched upon lightly so I can see why lots of children become fascinated by it. Doubly so if they've seen the film.
If in 100 years time they can conjure up the same glamour, intrigue and romance about the Grenfell incident then yes it would be comparable, but somehow I don't quite see it. Sympathies to the PP who knew someone who died in Grenfell, I'm sorry for your loss x