At a corporate level, perhaps they don't care so much, but if they really didn't, why make the effort to greet frequent flyers and provide top notch service?
I think with EK it has always been a mantra of providing everyone with good service, and a little better to the frequent flyers. Unlike the American way of treating everyone like ...., and treating the FFs very well.
A lot of people have mentioned the importance of delivering benefits consistently. And I also think these benefits need to be relevant. An upgrade voucher only usable on a Y fare is useless to most people - on many routes it is almost as expensive/ more expensive than an O or I fare.
Also, in EK's mind, the incentive for people to fly beyond 50k has been good connections and product, and given the number of people that fly over 50k a year, and the high loads the airline has, they probably see no value in spending more on some people to get them to fly over 50k.