Never thought of all this. Request to all: I may be perceived as a Maruti-Suzuki hater (which is true, partly) so please forgive me if I make some wrong statements. No offence meant to anyone, just because this is happening to me too often
While ESP is surely not possible (IMO again), Maruti doesn't really have to justify the price or be competitive in the market. I know many folks who shall never go out of a Maruti showroom. If they increase the mileage, it's going to be even easier. Even I was one of them maruti-guys, but many factors turned me against them. Swift shall be ever-green, don't worry. But then, tell me: How many buyers will ditch the V for the bluetooth and go for Z? Sensible ones would get to work in the aftermarket. Others would compromise. And those who can extend their budget will go after the Z variant. Oh, I almost forgot, ABS and Airbags are also a reason to go for the top variant. And tell you what, MSIL offered the Airbags and ABS on the top trim just for the safety ratings (they always use the topmost trim (?)) and to add another feature on the spec sheet. Agree many manufacturers do the same, but Swift with flimsy build quality? Now at least where I live, it is very rare to see a Z trim Swift (especially ZXi), and even those Z guys prolly didn't get the option pack. Now Suzuki cannot do much to change the thinking of Indians except few which they cannot manage with already a fine on their head. But all will take for granted: If they add airbags, not many will throw the Swift out of the list just because it is priced 20,000 to 30K higher than now. And about our argument about Bluetooth: You are right

Not leaving difference between models is what I (personally) hate.