Then please discuss this in a discursive fashion and set out your reasons? If you have an argument, this is not a big ask 
Waiting for the reasoned response....
Ok, then.
"Once you lose your Forward truck, its pretty much GG."
Not true at all. If you have even one building each one has a strong AT unit in it to keep you in the game. Schreked volks blobs themselves are enough to hold off most armor, especially with a little bit of puppchen support.
"Because you lost your Truck and pulling KT isn't 'I win' moment."
King Tiger is very easily a I win moment. If the allied player doesn't have at least 3-4 sources of AT it's over. Or atleast the decline will begin.
"IS2 or few Zis can take on KT just fine........."
An IS-2 will always lose in a straight up battle a KT easily. And I see KT literal stroll right up in front of two AT guns destroy them and then just fall back for repairs easily. AT guns alone are never enough to stop a KT.
"KT isn't really the issue with OKW balance"
It's why we are having this thread. There is a reason OKW is so strong late game and it's not because of pumas.
So yeah, everything he wrote. Just reverse it and you will be closer to the truth.