A square keyboard would take less time to navigate between keys!?
I agree, and I would bet most people that use the two different styles of the on-screen keyboard interface would agree.
It is so easy to make a mistake too, and it is much more effort to correct that mistake using the tvOS on-screen keyboard.
Luckily, some of the apps on the tvOS have a square style, but many of them adopted Apple's version.
Why Apple didn’t think this way?
Well, Apple had a new way of navigating in tvOS with the swiping of the Siri Remote. The style of on-screen keyboard reflects this new way of navigating.
I personally find that both navigating with the Siri Remote and entering stuff on the on-screen keyboard is very tedious.
There was also the Siri feature to enter in info, but this was very problematic. In tvOS 9, Siri didn't work that well. Also, not everyone wants to announce a password to their accounts to everyone around them.
But probably the
biggest reason for Apple to have the style keyboard that they do is that there is no D-pad on the Siri Remote which is ideal for the square style on-screen keyboard. In later versions of iOS, Apple added the pseudo-D-pad by touching the edges of touch pad, but their on-screen keyboard never changed to the more ideal style.
My guess is that Apple won't change it any time soon.