Yes, bad or mediocre ballets can be useful to the dancers and temporarily fun for the audience, but in the long run, the lowering of standards can only erode the art form we all love.
Tolstoy may be right about happy and unhappy families, but in ballet, it works the opposite way: All good ballets are different from each other and all bad ones are alike, at least in one crucial respect - they're all empty.
What guarantees - or at least semi-guarantees - good ballets is good choreographers, and they are thin on the ground.