Quoted By:
Japs are used to giant monsters.
They have many famous series like Ultraman and Godzilla, which is a core part of popculture, in fact many of the first Pokemon ever made (Rhydon, Staryu, Kanghaskan, Jyxn, Nidoking, etc) are based on giant monsters from Godzilla/Ultraman.
Dynamax is probably a gimmick that's going to ressonate more on its homeland than on the west, but still, I love to see Pokemon going way back to its roots.