More importantly, a fair number of those Spot Hidden rolls were scenario breakers. That is to say, if you didn’t find the door leading to the ghoul catacombs (or whatever) the adventure was effectively over. Here’s how that would work out in actual play, at least when I ran CoC:
Player: My Spot Hidden is 45%, I rolled a 63.
Keeper: Well you find the secret door that leads to the rest of the adventure anyway.
Player: Then why did I roll?
I know, I know, standard advice to GMs making scenarios is not to even bother putting in any rolls where missing the roll causes the scenario to fall apart…but that has perverse consequences. Your players will eventually notice that no matter how low their skill is with any kind of information gathering, they’ll never miss the crucial clues that move the plot along. It takes a particular kind of hard-core GM to trash a night’s entertainment, or kill a party, on the basis of a single botched die-roll or crucial skill that nobody bothered to take. So they’ll either a) stop emphasizing those skills (the munchkin approach), or b) take them anyway, because they’re in character (the role-player approach)…but the skills will still be deadweight, so in effect you’re punishing the role-player for being less of a twink.
If you follow Jeff’s approach, those skills become valuable again–how valuable depends on just how much you’re willing to screw them over on a missed roll, but it’s easily enough to make it so that they want to succeed without your having to hand them everything on a silver platter just to keep them from hitting a dead-end.