Probably because they are looking into the future and seeing those ports as becoming less and less useful.
Exactly. Because that crap is useless to some people. I need an optical drive and a bunch of USB ports on my secondary, portable laptop like I need a hole in the head. Totally useless for me. I would never use these things.
The MBA missing 'functionality' for these complainers means simply that it isn't the laptop for them. For some people it has good functionality. It isn't perfect (I'd like built in EVDO for example). But a lot of this 'funtionality' that you many decry is useless if you already have something like a Mac Pro.