This title and its predecessors weren't Zavvi exclusives and were readily available elsewhere.
It seems a little unfair, therefore, to blame Zavvi for their release in the Steelbook format. Surely, that was a decision made by Warner in the expectation that there would be a market for them.
In any event, Steelbook collectors, taken as a whole, have widely disparate tastes and I'm sure that the market is large enough to cater for these and other genres. It would be a very boring world if we all had identical tastes.