Looks like I can answer my own question. My MBA not only cannot backlight the keyboard - major disadvantage for me - it neither offers the option of ambient light adjustment.
Dropping those features consumes more of my time - I make more mistakes typing (and yes, I can type 'blind' but since I'm typing on a 'English' keyboard that has to be set up for German typing, I sometimes have to able to quickly see the keys properly to remember which key is which in German) and have to adjust the brightness. I switched form Windows because I was tired of wasting my time - so this is certainly annoying when Apple is doing that too - for no good reason as far as I can see.
Please Apple, do give me and other users enough credit. We really are intelligent enough to turn features on and off when we want them. Just taking them out will make me wonder what I will have to do without when buying Apple next time around. This is the wrong way of saving energy or whatever the excuse is! I don't think I would have bought the MBA without backlight if I had known. It is just too timeconuming for me.