The auction as you may remember emerged as an idea from the community(while NXT AE wasn't around and wasn't even a though) with the purpose to attract a good deal of attention and helping a lot of other people to join before our official launch(There was a high demand for it). After we did the NXT AE listing the auction remained in place because of the same reason and because it is still relatively hard for new people to buy NEM via NXT AE.
There is a big difference. Nxt AE trades are done among users. The auction money will again be controlled by the "developers". Why so much centralized money controlled by just a few people? That's in addition to 25% Nem that they will control and nothing yet known about what will happen to unclaimed stakes (could be 25% more -- potentially making total 50% controlled by a just a few).
If they want to do auction, how about doing it with their 15% of the stake (which is equal to
600 stakes a very big chunk)