Jim Starlin's drawing of Thanos (beginning with Iron Man #55 and later in the Captain Marvel run) looked far cooler and more sinister. In this film, Thanos has a moronic slackjawed look that seems like some half-assed variation of Ben Grimm's face. Must be another lame consequence of Disney's production. Don't want to scare the kiddies after all.
shareSpeaking of being more sinister, remember how Thanos literally worshipped death in Starlin's Captain Marvel? While Thanos was an obvious knock-off of DC's Darkseid, the name Thanos was derived from the Greek word for death, thanatos.
shareThanos was obviously redesigned so Brolin could motion-cap his heart out.
Plus, Marvel doesn't do scary or anything else challenging that might stop people from going to see their films.