The iMac doesn't have VESA mount holes either, yet there is a VESA mount kit that can be purchased from Apple for them. I'm sure this is absolutely no different. Apple is designing this to sit on a cabinet, and if the customer wants to wall mount, they will sell an accessory specifically for that purpose.
Wall-mounting a TV can be purely for aesthetic purposes. My TV is wall mounted, with the wires running through a conduit to a cabinet on a side wall, better suited for its placement and accessing the equipment. The TV is centered on the wall, with nothing else on it, no furniture, no wires, just a clean smooth wall. It looks fantastic. It's mounted at the perfect height for the seating in the room, which would have otherwise required the purchase of a custom piece of furniture to put the TV on a stand at the correct height -- a piece of furniture which would have had to be replaced if the next TV didn't have the exact same dimensions and stand height.
Also, the heat above a fireplace, usually is blocked from going directly up to the TV by the mantle. And the height can be perfectly acceptable depending on the seating arrangement. The TV in my bedroom is wall mounted much higher on the wall due to the fact that it is being viewed mostly lying on the back with the natural gaze of the eyes centered on the TV at a much higher angle. That mounting also works out much better when standing, getting dressed in the morning etc. Indeed, there are fireplace mounts which allow the TV merely to be stored above the fireplace, and pulled down for viewing. This works out well in many homes where fireplaces are mostly decorative, including gas fireplaces, which have very little heat output to begin with.
And finally, there's space concerns. Mounting any monitor on the wall allows full use of the space. At work, my monitor is suspended from the wall, allowing me to use the entire desk space under it. The same thing could be true of a home TV, even if an equipment cabinet is under it. Certainly that's true of my bedroom TV, which allows me to lay out clothing, accessories, wallets, etc. on the dresser below without worrying about fiting it on the space around the base of the TV. My Main TV has nothing else on the wall because it would push too far into the seating area eliminating comfortable walking space, and putting the closest seats too close.
Not sure why any of this escapes your comprehension ...