The definition matters if Larian does actually add passive checks to the game. This isn't to take away from the intent of the thread, but definitions matter. Passive checks are a specific mechanic we do not have in Patch 4. It is up the the GM whether passive checks should be in the game.
I can agree the perception checks in the game seem flawed. Only getting one roll for perception feels weird, usually you can get multiple checks in if you really want to find out what's happening.