I feel like you don't have a solid grasp on the clinical trial process. When the placebo group declines 5% in density and the trial arm increases in that same time period, that's your result. You can't apply dumb platitudes like "some maintain for years with nothing!" when comparing two mean data sets that are going in different directions.Maintenance is overrated though, especially in these short-term studies.
Some people more or less 'maintain' for 10 years with no treatment. If it can give at least 5% regrowth that would be something to talk about, so hopefully it delivers regrowth even if minor.
By your own logic, finasteride doesn't work either because some people maintain for that 5~ year period without it. This trial showed slightly lesser results then finasteride in a similar period of time.