In my opinion they make it vague because every single DM and their mom has their own opinions and rulings on how finding traps and then disarming traps is supposed to work. The more specific you make this spell, the more you piss off a larger amount of the DMs out there who now have a rule that goes directly against how they prefer to play the game. It's no different than the stealth rules... just enough to give all players a general idea of what you can do and how to rule it... but open enough that every DM can supplement it with their own additions based on how they prefer and choose to play the game.
Yes, that does mean a DM has to "do more work" in explanation to get the Find Traps spell to work the way they want it to... but better that then have it work the exact opposite way they'd want it to, right?
Yes, that does mean a DM has to "do more work" in explanation to get the Find Traps spell to work the way they want it to... but better that then have it work the exact opposite way they'd want it to, right?