They have a bunch of levers to pull to reach that target. Failing to pull the lever that reduces particle effects does not mean the game is un-optimized.
In game development, the process of identifying, balancing, and pulling those levers is called optimization.
Source: This, specifically game optimization, is my profession and I've been doing it for 15 years.
Edit: To add, this is clearly a vocabulary argument, it'd help your argument if you gave context and defined what you think specifically optimization refers to. But even then, words are used in context, and the context here seems to be strongly game development flavored.
They have a bunch of levers to pull to reach that target. Failing to pull the lever that reduces particle effects does not mean the game is un-optimized.