Movies are so subjective. And sometimes they are even more subjective depending on our mood when we see them. That being said, IMO, there are bad movies that are kinda' supposed to be bad. Like Sharknado and Velocipastor. Then there are movies that are supposed to be good, like the three and a half hour long The Irishman, which was about three hours longer than it should of been.
The worst film I saw all year was Ad Astra. Every person I spoke with who went to see it asked me the same question "How long until you fell asleep?" It took me about twenty minutes. And I don't fall asleep watching movies, especially in the theatre, especially in the morning.
Speaking with a lot of folks about it they all agreed it was "the best film to fall asleep to of the last ten years."