As other stated, the changes have nothing to do with their altitude equivalent, which is still mileage based and not downgraded from the current levels.

And the new redeemable miles equivalent, whilst a downgrade, is still more generous than aeroplan.

There is an argument for having some spend associated programme, maybe in conjunction with mileage. But switching solely to a spend based policy as your suggesting would take a huge overhaul, and more importantly likely annoy far more people than it pleases.

And has been said many times before... if you are spending in the region of 25-30k a year and not hitting SE, then you should hire an PA to arrange your travel for you... you're not getting value for money but that isn't the fault of the lower spending SE!

If you are spending that sort of money and not hitting target that tells me 2 things. 1, you don't fly internationally. In which case you don't really need the extra benefits of being SE. And 2, you buy a lot of lattitude fares, which means you can upgrade all segments domestically at anytime for 1 credit meaning you always fly J and never run out of credits. Both things suggest you aren't exactly being screwed by the system.