I don't know why anyone's complaining, it's not like they have to buy it.
Too many people seem to blame retailers for making them part with their money, from steelbooks to figure variants. No one's coming round to our houses and extorting money out of us.
Disney is the absolute king of repackaging their movies. Disney Blu-rays with no number on the spine, then a yellow oval number, then a white number, and villain slips, hero slips, complete set of matching slips, steelbooks and so on. If I was Zavvi (or any retailer) I'd want in on that action, wouldn't you? It's a licence to print money. Oh look, the Pixar titles are getting numbers on the spine too, go figure!
Germany did an iron Man steelbook, an Iron Man 2 steelbook, an Iron Man 1 & 2 steelbook (and that wasn't even Disney). Marvel titles are a cash-cow, whether they're MCU movies or not. That's why (in the UK alone - excluding the MCU), we have The Punisher (1989), The Punisher (2004), Daredevil, Elektra, Fantastic Four (2005), Lionsgate's animated series, the Spider-Man trilogy, The Amazing Spider-Man, The Amazing Spider-Man 2, all the X-Men movies and Hulk with many more announced already.
The MCU itself has had so many steelbooks released worldwide it's crazy. Ultimately I buy one steelbook for each film, I don't care how many variations of Iron Man, Thor or The Avengers there are, there can be 100 for all the difference it makes. But each to their own.