You can have a great Kirby-esque cosmic and goofy movie, like
Thor: Ragnarok. Or you can have a great somber, serious movie about a Batman concerned with his own mortality and legacy (like
The Dark Knight), plus touching scenes featuring a grieving woman whose boyfriend comes back from the dead. But
mixing the two is kind of like
mixing hot steak fresh out of the pan with peppermint ice cream.
Justice League is too ponderous and grim to be jolly good fun, and too
Power Rangers-level stupid to take at all seriously. There simply is no
there there.
And Tolkien is one of the great fantasy writers, but Tom Bombadil still had zero place in PJ's
Lord of the Rings movies. (And if you don't get the Freudian connotations of "Mother Box", well...)
At least the MCU had the good sense to rename its Cosmic Cube "The Tesseract" - and there's good reason Hugh Jackman never wore that stupid yellow mask.
Seriously. It was soulless corporate product, featuring the fifth gravelly-voiced revenge-seeking villain in a big-ass ship in a row (yes, the swarm of little ships count as one "big-ass ship), the action editing was
horrible, somebody gave Pegg a prank script with the word "lassie" included five times per sentence and nobody noticed, the movie gave me a throbbing headache, such that I never, ever intend to see it again,
and it underperformed. So, yeah, fiasco.