Ok lay it out for me how this is 'common sense'. It's 'common sense' for me for them to make all the content they want for a certain expansion, and then later add in extra items they wouldn't have normally made, for the store.
Think of league of legends. How many skins are in that game? Do you think they would have made all of them available specifically for rewards in game? No, most of those are extras that they wouldn't have ever even thought about making if they didn't have a store.