1 reason for me - thanks to our great distance to anywhere else in the world, just one Star2 RTW trip with a very small side trip added in gets me Elite, but more importantly the treasured *G and it's benefits like lounges, luggage etc. (As long as I don't do domestic Canada on the RTW else I'll be short some status miles because of the H class rule.)

It's the best value around bar none.

Apart from that, have a partiality to Star over the other options, even despite the lack of a local * carrier. The more "local" carriers (NZ SQ TG) schemes don't come within a bull's roar of AC's or UA's with the sort of flying I do. If AC wasn't online here, then maybe I wouldn't be in it.