But how often do you do those things on the move? I do those things back at my desk, and so I have the multi-port adapter and a USB hub for that. I like having only one port, it's clean, tidy and helps the rMB achieve the form factor it does.
But you would really want ethernet to do that with a large dataset and you couldn't project and use ethernet at the same time on a MBA. The MBA is pointless it doesn't have enough ports
rMB is fine, the ports issue is not an issue, just an excuse punted by MBA owners to bash a better, more modern product thats mad their device obsolete.