The movie sucked. Sucked hard. Even when I was 9 and seeing it on the big screen, I realized that. Not only was the writing/acting/directing all fairly lame, but the movie actually had a whole bunch of mistakes and inaccuracies about various Nintendo games. ("Get the STAR, Jimmy, it's worth more points!") That's just inexcusable, as the kids in the target audience pick up on bullshit like that right away.
$14 mil in box office, yeah. But how much did it cost to make? Hell, at the time $14 large probably just barely covered the salaries of Fred Savage, Beau Bridges, and Christian Slater combined.
And yes, the movie did help sell merchandise. Specifically, it helped sell one Power Glove to yours truly. And THAT moment is the first time I realized that video game companies and movies would lie to me and sell me horrible useless shit just to steal my money.
On topic, what other games has IGN ever given a 9.8 or higher score?
It was a bad decision on the movie studio's part, not Nintendo. They didn't make the movie themselves, they got paid so that a movie studio could give them free publicity. That's an incredibly good decision, because even though The Wizard sucked, I'm sure nobody was turned off to Nintendo because of it.