How to reproduce:

1. Open attached project
2. Open scene test.unity
- Scene contains about 100 particle emitters with their start lifetime set to Random between two Constants (1 to 10)
3. Open the profiler
4. Play the scene
5. Switch back to the scene view and look away from the particles
- Note how the profiler displays that the particle systems are still active and doing something
- Modifying the particle emitter prefab to have its start lifetime set to Constant (10) and following the steps from step 4 makes the particle systems in the profiler appear inactive