Doesn't history tell us the original cooking pan of preference from the Balti triangle was thin pressed steel? This contradicts the theory of aluminium being an absolute necessity. My guess would be that aluminium pans are used for more mundane reasons due mainly to economics.
As a good thermal conductor it is faster to heat, Less gas and time spent waiting is more profit and therfore good business sense. Being lighter in weight saves energy, both human and heat, not that I'm suggesting the curry chef will tire more readily by using steel pans. Also as a relatively soft, and malleable material, easily formed into pan shape using the spinning process, aluminium pans are very cheap to manufacture. I think the shallow shape of the omelette pan is also a pertinent factor as well, hence, it's common use.
My pressed steel woks get plenty hot over the gas hob but I'm going to buy some aluminium curry pans anyway for all of the stated reasons which are just as valid in the home.