How is this tantamount to deciding which companies are good and bad? Mozilla have simply identified an extremely common way people are tracked online and are doing their best to contain it.
Same rules should apply to everybody. You should be able to decide some rules, even heuristics that can catch tracking across multiple sites and suggest user to disable it rather than pointing to entity and applying different rules to it than to everybody else.
You can set up containers for every domain you like. Facebook just comes as a predefined option because 90% of users are going to choose that domain anyway.
