Actually, it makes sense to me on a couple of levels. Until very recently, the overwhelming majority of tablet users were using iOS--that is where the market was. The iOS team (led by Jim Dovey) is definitely the most experienced of all the app groups Kobo has. Additionally, the iOS app had a huge problem that started around the time Apple made in-app purchasing financially a loser, the iOS app wasn't syncing correctly.I am sure that Kobo through a whole lot of development time at the iOS app for both of these reasons.
My sense is that the Vox came to market a few weeks early because of market changes and that the Android team is playing catch-up. I suspect that having one team solve a problem and then adapting the solution to a different platform makes more sense then having a bunch of different teams working in parallel. At least now, as the Android team works its way forward, they will have the iOS lessons out there for them to learn from.