Exactly. In the game, there is no downside to checking for traps -- or checking every square inch of a room for secret doors, etc. -- unless the DM constantly forces some urgency, which may or may not make sense.It may also not be paranoia so much as making a "strictly good" decision. I mean, if you don't search for traps, you might get nailed by one. If you do, then either you find a trap, or don't, and if you don't you're just as badly off as you were before.
I agree, that's a great key game decision to make the players decide.
Uh, what did you say?
To the poster who was annoyed that his players were sure that there had to be a secret door at the end of a ramp leading to a blank wall? I'm with them, there isn't any good reason for it to be there. This also goes hand in hand with the roll/role playing debate. Here's a situation where roleplaying informs the characters that there has to be something there, vs. rollplaying (or, in this case, metagaming) that tells them that there isn't. So, which do you want? If its roleplaying, make the world consistant. If its metagaming, let them know ahead of time.
In addition, I think I have found a solution to deal with this to a small extent:
Impose a limit of time on reaction.
"You look through the door and see a bunch of guys conducting a ritual. They're chanting. You can tell it's almost finished, and whatever they're going to do, it's going to be bad.
Everyone at the table, you have ten seconds to decide what you're doing."
I had to impose a 'count to ten' situation when one PC wanted to run away, one wanted to stay and fight, and one was wishywashy, in a situation like this, and no one at the table would agree what to do.

If people are obsessively searching for traps out of the fear that unknown bad things will happen to their characters, making them choose between two unknown bad things is not going to be a practical solution. They're just going to be afraid of both and either seize up or panic.
Really living up to your namesake today, Eh?!

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.