Got nothing to do with being humanoid.

Bipedal predators are a rounding error, probably the most effective hunter/killer robot would be dog shaped and medium dog sized, with a back mounted turret.

Give it pack tactics, with radio comms…

Why the hell does anyone think it’s still a good idea to make robots that are significantly stronger than humans?

So they can easily do tasks better than a human or that a human could not possibly do. Like moving heavy furniture unaided.

If you consider the mentality of fascist dictators, the concept of an ever obedient non thinking workforce/army is very appealing. That’s why.

Could it end badly even for them? Sure, but heck, if they don’t make the human race ending robots, someone else will.