Been that way forever. Not a 'new' and 'conscience' decision.

I bet AA would LOVE to see us book all our miles online so they could get some of them miles used up. Come, waste your miles online and when you cancel an AAward trip we charge $100 to redeposit your miles too!

Part of the reason that partner/OW members require the booking over the phone is the lack of instantaneous confirmation of the AAward seats from the other carrier. If you have ever booked an AAward, you will notice it takes a lot longer to go to 'ticketed'. Your reservation on the other airlines is really a REQUEST for reservation for the AAward and subject to confirmation by that other carrier. I booked NRT-HKG on CX recently and it took several days to get a 'confirmation'.

Now the next complaint will be 'I cannot select my seats on the OW/Partner carrier for an AAward'. And that too is true. You can only select your seating based on the other carriers 'system' for selecting seats. CX, for example, only selects 6 months out (vs AA 330 days out for seat selection). Some carriers do not assign seats for AAward travel until airport control ..

There are a lot of holes in the whole OW process. It is not 100% seamless .. but certainly pretty decent.

Call and book your trip.

Ask about seating assignment and follow the AAgent's instructions. You may have to contact the other airline directly.