Because it's not unreasonable to disagree with the law. The judges may be applying it correctly, and correctly following the process for determining that the market is all mobile apps, and not just iOS mobile apps, but it's reasonable for people to disagree with that on first principles.
The legal definition of a monopoly has been refined over multiple decades of case law, I would argue that you can’t have a meaningful discussion about whether a company is or isn’t a monopoly without framing it in that context. And yes while it’s reasonable to disagree with the details of the law, it’s another thing entirely to make up some arbitrary criteria in your head and then declare some company is a monopoly based on your imaginary criteria.
