Winning at penalty kicks is luck friend. It's a leap of faith for the goalie more than anything. So yea, winning a match that the other team was dominating like that is definitely luck.
And as for wanting Brazil to get booted, it's the fact that they're playing like crap and winning because they're Brazil. This is not the Brazil I grew up watching, and it sickens me that people want them to move along just because they're hosts. It means that the level of football won't be the same in later rounds, and in this case Chile leaving is a goddam shame because, unlike Brazil, they actually showed drive and mettle.
So no, it's not conspiracy theories, although the idea of Fifa being corrupted and favoring a Brazil and Argentina final is not even a secret.