Why so negative about aircon'ed tents ?

I think it is more viable than say, building massive apartment blocks just for this one event. The total carbon footprint (someone mentioned it previously) will definitely be less.
It may even be a selling point for its 'exoticity' and 'bedouin-ness'.

Another alternative is course taking a leaf out of the ASIAD's book: mobilizing squadrons of cruise and hospital ships to be used as temporary accommodation.

Cheers
SK