Why is Povetkin's victory a TKO?

Cos no count there. Still it was very serious KO. > 30 sec till he get more or less coordinated after this punch, not alone to fight this or next day.

 

TKO looks better than pure one-punch KO to a casual who is flipping through boxrec in 5 years when we're being served Whyte-Joshua III: This Time The Loser Really Leaves Town

 

His head didn't come off. It was clearly still connected to his body by his neck, mostly.

 

for casual KO in boxrec looks more impressive than TKO because descriptions what is TKO are longer and casual fan does not like to read long texts.

 

TKO sounds like "it wasn't actually a knock out, but let's count it a knock out since the defeated boxer couldn't continue the fight", so it is belittling the winner's victory.

Ruiz's victory against AJ was a TKO, the referee decided AJ could no longer continue the fight although AJ was conscious and standing on his feet.
Whyte on the other hand was in deep sleep and counting the sheeps while the referee was waving hands. It wasn't a KO, it was a KTFO.