I think the real problem ties to ego. I'm a fairly smart guy. I do tend to think of things to ask the GM or strategies to employ that others do not. Therefore, it is a little annoying when I ask about X and fail my knowledge roll because my PC can't be good at everything, that every other player jumps in and eventually gets credit for it because everybody remembers the guy who succeeded and got the answer which required a lucky die roll, not the guy who actually had the brains to figure out what to do.
It's a disconnect of the player ability vs. character ability. Saying "here's an idea, I'll attack with my sword!" isn't particularly rocket science and isn't particularly disconnected from the PC's +5 to-hit with his sword.
Whereas, me thinking to see if I can recognize that small ash pile as to what type of cigarrette it came from so I can match it to the murderer (ala Sherlock Holmes) is fairly clever on the player's part, but not reinforced on my PC's part when he roll's a 1. It further sucks when the next PC roll a 20, and has a better modifier, and then gets all the credit for solving it, when all he really did in game terms is say "me too!"
My preferred approach is to either give the information automatically in response to a request, or else use low DCs, but only give a roll in response to relevant action - so if you are playing Sherlock Holmes, put a few points into relevant skills, and if you ask the right questions you will likely auto-succeed.
I don't like players expecting to auto-pilot through an adventure, merely rolling dice on request. I once had a situation in 4e where the PCs had captured an obviously evil dwarf slaver. He offered to help them vs his bandit allies, if they returned his crossbow. I used an "I am an obviously lying sonofabitch" evil dwarf slaver voice. The PCs happily returned his crossbow, no one requested an Insight check - and when they encountered the bandits, they were very surprised when the evil dwarf started shooting at the PCs!

Some players complained - they said I should have had him make a Bluff check, and have them make Insight rolls, then when one of them succeeded I should have told the players he was lying - without any PC even having raised that as a possibility! Well, screw that.