Management normally defines ways to track and judge itself, these are typically called Key Performance Indicators.
KPI's are normally things like contract value growth, new contracts signed, profit margin, etc..
So if the project manager is meeting or exceeding their KPI's and you walk up to their boss telling them the PM is failing as basic job functions, the boss won't care.
This is because the boss might have set the KPI's or the boss might also be judged on them. In either situation its to the bosses advantage to ignore you.
The boss will only care if there is a KPI you can demonstrate the PM failing to meet.
Every person/group will have various incentives and motivations. To affect change you have to understand what they are.