Also: rule of cool.

That seems to be the answer to pretty much all the weird stuff you see in MCU movies. If it’s cool, they’ll throw it on the screen. If not, there’s a pretty good chance it gets cut before release.

The original comic books may have evaluated various decisions in the same light, but it really depends. Some comics were highly whimsical, where anything goes, while others were more serious and dark. I haven’t read the original hulk comics, so I can’t really tell if it was meant to be harmless fun where nothing is taken seriously.