Is it fair to call a movie bad if you walked out before the ending?

Here is the plain version. A movie is a deal. It asks for two hours of your life, and in return it has to earn your attention along the way. If it hasn't done that by the one-hour mark, it has already failed at its job. Walking out is just you reporting the result. The 'finish it first' crowd says endings can redeem everything. Sure, a few might. But that's a bet, and most of us don't have infinite time to place it. If a film needs me to sit through sixty dull minutes so a twist can make them retroactively meaningful, that's a design flaw, not a defense. A good ending that arrives after I've stopped caring is a good ending for someone else. Also, think about how we treat everything else. Nobody says you can't call a restaurant bad because you left before dessert. Nobody says a song is off limits for criticism because you skipped the last chorus. If the first course was inedible, you're allowed to say so. To be clear, I'm not saying the walkout verdict is the whole story. You can say 'I left at the hour mark, so I can't speak to the ending.' That's honest and it still counts. It tells people the film lost someone, and that's real information. A film that makes people leave has told you something about itself. So yes, walking out counts. It may not be the full review, but it is a review.