We've done this as well.... or they've allowed us to walk up, but made us wait 20 minutes only to seat us in a near empty restaurant. It's a buffet people. Put in a coffee/juice machine and the entire floor could be ran by a staff of 2 people.
I agree with you... why? Makes absolutely no sense.
Ate at the TE tonight for dinner (damn delicious). Tried to walk up, because hey, it's always half full. It was a bit busy in front with the hoop de doo shift change, but they told me no walk ins. So what's a guy to do? Well, I'll tell you....you open up your disney app and pick one of the 10 available times, walk back up to the podium and get shown to your table in a half to 3/4 full restaurant. Why do this? I watched several families get told the same thing and walk away. Best part was, it was getting late and there were piles of fresh food left....all to be thrown in the "compost pile" as I was told.
Makes no sense, unless you make so much money you no longer care. A regular person just can't comprehend their logic.
Did I mention it's still tasty as could be?
Happy reservations!