IMO a fun movie doesnt equal being good.
The godfather is a great movie, but certainly not fun.
American Pie is a fun movie I can watch again and again, but I'm aware that it's not a good movie.
Roadie holds the fun of a lot of Meat Loaf featuring, and so might be considered a cult classic among the fans. I personally have seen it two times I think. It's quite enjoyable to watch, but I dont worship every single line or scene.
Also I've noticed that it's mostly women who think Roadie is a cult/great/good movie and watch it endless times. Might be something to do with the old Loaf fancying