What bothers me is calling something "passive" when it isn't "passive" by any definition I know of. "Standard, typical, or routine" would all be better choices for the terminology.
From
Dictionary.com:
6. influenced, acted upon, or affected by some external force, cause, or agency; being the object of action rather than causing action (opposed to active def. 6). Related to the grammatical definition, that is, the "passive voice": a passive verb describes
being acted upon or
receiving the action rather than the thing
doing the action.
In that sense, "Passive Perception" reflects being acted upon by the world around you. As I said above: you literally cannot choose not to observe things while conscious. Hence, even if you aren't
looking for anything, even if you are putting out zero effort whatsoever, you are still looking
at things and
hearing things etc. You just aren't listening intently for whatever might come up or carefully scrutinizing for a specific detail.
Now, it may be the case that you think it's dumb that passive observation gives
that much of a bonus. That's your prerogative, you can do what you like. But the term "Passive Perception" is perfectly in keeping with the way the word "passive" is used to describe a variety of things, including the
literal actual scientific practice called "passive observation."
Someone upthread even described it as "passive sonar"...
Because that is an actual IRL thing. Passive sonar does not emit any pulses; it simply waits for ocean sounds to come to it. It's still
listening, it's just not doing anything active to
create sound patterns that can then be observed. That's why it's passive, as opposed to active sonar.
(You could think of ordinary human hearing as a form of passive sonar, while bat or dolphin echolocation is very much active sonar.)