I happen to be an adult collector, and will always prefer a SteelBook over a digibook.
Having said that, I actually like the TLM SteelBook and don't see it as a half-assed effort. Sure, it is artwork we have seen before, but it is the only SteelBook option and it is not bad artwork. It is simply reused, but it is, in my opinion, one of the best pieces of art from the film.
You can argue that TLM is a kid's movie, but I can argue (and I think Disney will side with me) that it is an all-ages film which everyone can enjoy, and yes that includes adults and adult collectors.
Disney and Target are both well aware of the huge adult collectible market for Disney. Nevertheless, Target has decided to produce an exclusive aimed for kids. I'm not saying this is wrong, and in fact, it may very well be the smartest decision from Target because it will move sales for adults buying for kids. However, I don't have to like it.
I collect digibooks because of the extra information about the film. I don't buy the digibook for E.T. just to have a kid's storybook in it.
Maybe others are fine with it, but I am not. I know that as a storybook it will never be read by me and would just sit on my shelf and collect dust. I would much rather have a nice looking SteelBook over a kid's digibook any day.
Even as a digibook collector, I'm not interested in the digi for TLM. I actually did buy both the SteelBook (German because I like blue) and the digi for E.T. because I liked both. Same with JAWS.