09:33:16 PM Mar 4th 2016
"However, assuming that the Square Cube Law is still in effect, and they still don't collapse and die, then this trope is justified because the creature explicitly needs to be superstrong and massively durable simply to withstand their own weight " Uhh...wut? Forces sum, something being big and having enough strength to overcome gravity in no way implies that it would have the additional strength necessary to throw buildings or withstand bullets. In fact, a larger being is more likely to go all "exploding whale carcass" from a small wound (as a result of the internal pressure due to gravity).
09:37:43 PM Mar 4th 2016
Also, meant to say as an example: large land animals generally move in a very methodical, coordinated, and usually slower way compared to smaller ones. While their bones and muscle are sufficiently strong to survive gravity...that doesn't mean they are strong enough to go unharmed from the additional impact force if they tripped on a rock and fell over.