I guarantee you'd see actual bitching and moaning if their gesture was a DVD copy. They didn't have to do anything, I get it. It's great of them and all, but they should have either provided the 3D version just like what was in this set since that's what a good amount of people buying it wanted, or perhaps provide an offer to upgrade to that for like $5 more or something.
And let's not be naive and think Amazon is doing this just because they're so damn nice. They're doing this because they know this delay will inevitably lead to mass cancellations from people who want to buy The Avengers at release. This is being done as an act of good faith in the hopes that you extend it back to them and keep your pre-order for the pricier set. They are still a business last I checked.
very simple solution to this if its not to your liking why dont you just buy the 3d version and get what you want instead of thinking they should give you the 3d version because its not to your liking.