Fine then, please explain how "These characters don’t contribute their passive Wisdom (
Perception) scores to the group’s chance of noticing hidden threats.", even transformed to " the party’s chance of noticing hidden threats." or even to "the adventurers' chance of noticing hidden threats" means that ONLY for THAT adventurer, he gets no Passive Perception ?
This is ridiculous, the effect is clearly upon the group, the party, all the adventurers, not towards a single one. Why insist on that reading ? Why do you insist on changing words on a simple sentence that is clear and absolutely not ambiguous just to support your views ?
Honestly, you can behave the way you like at your tables, you can be as harsh as you want with your players because you want your level of verisimilitude, or want to run a tough environment or whatever. But please, assume that and live by it, and stop trying to modify the sentences in the RAW to give it another meaning. What would you say if I started changing other sentences in the rules, for example, that in the sentence in fireball "Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw.", it's not really each creature, it's an individual creature, and it does not really mean "make a saving throw", it means "dodge"