"Obvious locations" is a form of telegraph. If a player is thinking, "This door to the treasure room is probably trapped" then we are talking about player skill, right? That's why the only way to not telegraph, at all, is to place them randomly.
Or maybe you had a different idea in mind when @
iserith and others started talking about 'telegraphing'? Maybe you thought, oh, I don't know...how about: signs that say "trap here". If so, I'm glad we had this little chat and cleared that up.
Now, I think 'obvious locations' is a particularly
uninteresting form of telegraphing. Sure, it still relies on player skill, but not a very engaging or rewarding form of player skill. Or really very much skill. I never get that little rush of satisfaction, the one that I get when overcome something novel and interesting, just because I remembered to check for traps in an obvious place. But, hey, it's telegraphing.
"Devolve"? No.
Play that way in the early 1980's because that was what the adventures required, and even because it seemed fun at the time? Sure.
And, anyway, I was pretty clear that I was just trying to enumerate the number of ways that one
could play with zero telegraphing (not even "obvious locations") of traps. Checking every 5' is one of those ways.