I think they're considered 'premium' by those who don't know or own any releases from Czech Republic's FilmArena, British EverythingBlu, Italian CineMuseum, Korea's NovaMedia, Hong Kong's MantaLab, China's HDZeta and BluFans, etc.
All they add to the steelbook is a tiny metal pin, which is housed in a thick clear plastic overlay, making the package twice as thick, to portray its 'premiumness', if that's a word. Oh, and a folded six ways poster, which noone will ever hang or look at more than once (always say that paper and ink could have better been used to make 4-6 photocards).
If the steelbook itself is nice, then it can be a worthy purchase. Especially a few earlier releases, which had those mini steelbooks for the pins, I really loved those, imagining movies on MiniDisc being issued in such packaging in an alternative universe.
So V for Vendetta and, especially, Fury Road, are really good as steels.
I prefer matte steels as well, but my father was polish-german, so I guess that 'fits'.
That's hoarding, 'just to have'.
Not going to theaters past 10 years, and downloading almost everything, before buying, I tend to leave everything I've watched on an HDD and didn't absolutely hate, 'just to have it'. I now got over 40 external drives...
Others do that with discs, although my collection has filled two rooms and spread into the corridors, I consider myself buying only strictly according to my [bad] tastes, genres and categories.
There's a guy on YouTube, and I don't like to badmouth a fellow collector, who is buying everything from thrift stores, at $1 to $5 max. I consider his accumulation as hoarding trash. Has a whole basement of that crap, doesn't even wipe them down. Gets things on account whether he has it yet, or not. And with all that his worldview is, of course, very limited, very 'american'. Coming across titles like Koyaanisqatsi, or films with famous French actresses, he doesn't know what they are, so leaves those. It's disturbingly appalling.