Except, well, I don't care. All my images derive from ubuntu, so I pay the download cost once, due to docker having this whole delta thing going on, and storage cost really isn't a problem. Developers know how to apt-get usually, so that's less support cost on me. In fact, most of them run ubuntu themselves, which is a massive help with dev to prod parity. Oh and of course, there are more packages and a whole lot more forums/community etc etc.