If you put your Amex corporate hat on, it's a perfectly logical business decision - maximise profitability without losing too many customers along the way. Easy to do in the Australian market where they have minimal competition in the luxury card market (only Citi Prestige comes to mind with the $700 annual fee). So over time they have done the following:
1. Increase annual fee ($1250 to $1450)
2. Adjust churning ability (ranging from flexible eligibility for sign up bonuses (eg only restricting to cardholders who haven't held the particular card in prior 18 months to the more restrictive condition of holding any amex card in the previous 18 months. In overseas markets they're now excluding former supplementary cardholders from being eligible for sign up bonuses, not yet in Aus)
3. Cut back on benefits (eg devalue points like the partner transfers, cut back amex offers, kill off the concierge etc)
4. Reduce/cut off retention bonuses
Evidently we now seem to be at step 4 since Feb this year. So long as the cost/benefit ratio works out in our favour, most will remain sticky customers. The proposed RBA banning of card fees will put more pressure on card companies, so expect them to look to recover those lost profits.
