The view from the other side would be, do you really want your airline's primary hook with customers to be your frequent flier programme, or would you rather spend your capital (or defend your margins - as each customer with status using a new tier of benefits is a quantum jump in costs that need to be accounted for - e.g. baggage allowance, lounge access and most importantly for the airline additional mileage accrual) on investment into things like product and network frequency.

We have quite a few case studies of what happens when you value your frequent fliers a little too much and it is difficult once you give something away for good value, to take it away again - look at the uproar on the EY forum after their recent devaluation.

Much better to start off with a position of being stingy so customers know exactly what they are getting and so don't grumble to the extent that they throw their toys out of the pram when you make changes - if you don't catch every single frequent flier, it's not a problem, especially as EKs source markets are deep with a pool of enough once a year VFR fliers that they can still fill their planes. After all, the money of a frequent flier and a once a year pax is the same for any given seat. It's only that the frequent fliers generally give you that money more often, but if your loads are high anyway, it doesn't matter too much - perversely, you might not want that many frequent fliers as their margins would be lower for the same seat

That said, you could argue that a frequent flier is more likely to buy expensive fare classes - but then the argument to counter that is that those fliers who are buying short notice, expensive tickets are more motivated with schedule and flexibility (read: corporate travel policy) rather than the program.

Always a few who slip through the net, but you can't design a frequent flier program around outliers.