Add to that, the you tube crowd (and me) are probably not hitting the jumps in the lower gears. I hit jumps in third that I know my bike can clear in second. Why do I do this? Because accelerating into a jump that hard, in the lower gear, tends to push the front wheel into the air (a situation where you want your weight over that front wheel to keep it down) whereas the higher gear provides a more neutral flight which allows me to be in a more neutral position at takeoff. The downside to my method is simple, the bike doesn't accelerate nearly as well in the higher gears.