It dismissed the first 3 (valid) points by saying that Zombies are toxic...for some reason. Essentially just saying they're magic. Where's that come from?
Did YOU read it?
The link you're trying to debunk treats Zombies as infected humans, with the same essential weaknesses, and moreso in some cases on account of being reanimated dead flesh. Yes, very strong, and a wound that kills a human only slows a Zombie down, but still starts with a human.
Whereas your link starts with making up new facts based on nothing, and then using them to debunk other things. Not a point in its favor.
As for your last points: why wouldn't predators have a field day? Zombies can't (usually) run, can't use weapons, aren't great tactical minds. Mostly just stumbling around. Why wouldn't large animals have unlimited free meals, once they realize the humans aren't shooting anymore, aren't ambushing or laying traps? Might not be 100% kill rate, but think the wolves/dogs/lions/etc have a field day there with free (rancid) meat.
Assuming no other zombie magic, and that zombies are just reanimated corpses that are strong and not reactive to pain/major damage, seems like the points in that link work a lot better than what you're quoting in ZSG...
The reason for it saying "for some reason", is because that is one thing that does vary from movie/book to movie/book. Sometimes, it bio-warfare that infects them, sometimes it's moon rocks, sometimes, it's just unexplained and characters believe it's Revelations with the dead walking the Earth. The rest of the Zombie are fairly consistent in modern Zombie stories (Must damage the brain to kill, bites or scratches infect you, etc.). About the only other important rule that varies is wether you turn into a Zombie upon natural death, versus being infected, and typically a natural death will also give you Zombie-itis in modern Zombie movies
One Day I hope to be the Man my Cat thinks I am
Where are we going? And why are we in this Handbasket?