I can see why you might think that, but I follow David Pogue's blogs and I think he's just giving his professional opinion. He's a former contributor and announcer for Nova on PBS and he now works in the tech review department for Yahoo, so I don't think he's connected to Apple in any way.
Absent Amazon Prime, it is bit of a weak sister as it stands today. Going forward, it will continue to suffer from the absence of YouTube 4K support by decree.
The Wired UK review indicates that the Apple TV 4K is the only box on the market that automatically upconverts everything (and apparently not very well in some cases) versus playing it in native mode. Apparently if you want to view something in native mode, you have to go through the menus to change the output to whatever mode is appropriate.
The 5.1 sound limitation is probably okay for most who would otherwise be watching iTunes on a tablet or phone.
Of course this doesn't consider what Apple could theoretically do (if dragged, kicking and screaming) or what they have hinted that they might do (perhaps adding an auto-switch output mode).
For that kind of money, one should expect a box that is substantially unconditional in its capability. Promises of future apps and games are just words when you're going up against some very established players.
You tube 4K support could be done within the app if YouTube so desired. That said while there is lots of 4K on YouTube, most is just clips from what I’ve seen, nothing of real long term value.
Video mode switching is in the current beta, so I? expect that to not be an issue going forward. And the sound limitation is an irritant, but Apple has indicated that bitstreaming will come along later. That said, most houses I’ve been in with Apple TV didn’t have any gear that would support more than 5.1.
The Wired article suggested that the support isn't available in hardware for VP9 that is also used by Google TV for UHD. You can get other content in other formats but apparently all UHD content comes in VP9. We won't know if that's true until Apple comes out with something based on the A10X that is UHD capable (I suppose the same goes for the A11). The Roku, Fire TV and nVidia Shield all support VP9 in hardware.
As I said previously, a box that costs that much shouldn't have any significant limitations compared to the cheaper entries in the field.
And don't forget, good 4K will require better-then-most-peoples'-broadband connection speeds. Many of us in non-major cities or in the techno-slums are lucky to get 12 Mbps, let alone 25+ needed for 4K.