Cannes is the self important boobs in the entertainment business at any given moment.
If the studio thought it would be such a flop how did it open in so many theaters? Those prints weren't cheap to make back then, and they weren't fast to make either. Maybe before production started they thought it might have limited appeal, but once things got rolling everybody knew they had a hit on their hands.
I don't decry Spielberg because his movies are popular, I decry Spielberg because popularity is the goal of so many of his movies. He sold out his artistic vision for dollar sign vision. My problem with Spielberg is that he CAN be a brilliant director, but he stopped putting in that level of effort, now he's a mass market director still called an artist because of his occasional "important" movie and the rep he built in his early struggling artist days. He's got a fine sense of what the mass market wants, but that doesn't make it art, and the way he's willing to butcher a good story for the sake of the mass market has destroyed his artist credentials for me. A director with artistic vision says "the story calls for this, and that might cost us a little at the box office but that's what the story calls for", Spielberg doesn't do that anymore. Now he superglues happy endings on stories that shouldn't have them, and sticks enough product and logo placements in his movies that they turn a profit before the first audience member pays for a ticket.