You can say whatever you want, but you usually need a solid case to do this, and clearly you don't, since you have not found even one sentence in the rules or the devs intent to support you, se below.
I'm not dismissing it, I'm applying when mandated, which is better than you choosing to ignore words in the rule when they don't suit you.
Don't you think that, if the rule wanted to say that characters engaged in activity simply don't get a passive perception check for surprise and noticing creatures, it would have been written that way, rather than "not contributing to the group success ?" 5e rules are simple and straightforward. Ignoring words to suit what you think is the intent, when actually the devs themselves tell you taht you are wrong, is simply absurd.
And I have shown you the intent from the lead developper, which tells you, once more, that you are wrong about the intention, just as you are about the rules, since the intent, written again and again and again is that passive perception is always. Do you deny this ? Do you have any supporting evidence that the intent is as you claim ? No, obviously, since you would have produced it by now. So you are wrong about this as you are about the rules.
Look man, just read the PH, OK ? The whole game does not think that travel is important in general: "The DM can summarize the adventurers' movement without calculating exact distances or travel times: "You travel through the forest and find the dungeon entrance late in the evening of the third day." Even in a dungeon, particularly a large dungeon or a cave network, the DM can summarize movement between encounters: "After killing the guardian at the entrance to the ancient dwarven stronghold, you consult your map, which leads you through miles of echoing corridors to a chasm bridged by a narrow stone arch."
Sometimes it's important, though, to know how long it takes to get from one spot to another, whether the answer is in days, hours, or minutes. The rules for determining travel time depend on two factors: the speed and travel pace of the creatures moving and the terrain they're moving over."
So, sometimes, it's important, and you use the travel rules. Otherwise, it's just a summary from the DM.
Please stop with the OneTrueWayism of "Because I need the travel rules to impose a restriction on perception - that I'm scared of - everyone has to use the travel rules all the time, otherwise they are not following the rules and this is contrary to the intent of the game". The game has no such intent (passive perception is always on, word of the lead designers, so deal with it) and travel is a small subsection of the game, that is generally ignored and summarised by the DM, because it's not as interesting as actually exploring, fighting and having social encounters.
I'm cutting the part where you insult my way of gaming and again claim the high and mighty position of following rules, which is funny because you don't even read the one sentence that you like to its end.