Absolutely. I would like to experience all the little things that a dev has put into the game, hidden or not. In the case of "Find 100 _____" such as in assassin's creed, I find there is no shame to using a guide as there is no value in finding all the items.
GTA III did it right. For every ten items I found, I got a new item respawn at my hideout. That was an in-game incentive to find the hidden items. In Assassin's Creed, I just have to find them for the sake of finding them. That just isn't useful and as such I use a guide to get the achievements.
If the devs aren't willing to have a reason to chase all the collectibles, then why should I hunt them down.