Frequently, a motorcyclist will adjust his/her front forks up or down in the triple clamps to change trail and rake on the bike.
Changing trail and rake on a motorcycle can effect the handling of the vehicle and change the weight distribution under cornering and braking.
Increasing the rake makes the bike more stable at higher speeds and decreases responsiveness of turning input at the handlebar.
Decreasing the rake makes the bike more prone to speed wobbles (at the extreme) and sharpens turning input responsiveness.
By raising the forks in a set of triple clamps there will be more weight distributed to a motorcycles front wheel. Where additional wear can come into play is corning with the added weight. This makes the turning much sharper and requires less energy/input to perform the turn. This will wear out a tire much quicker than an opposite fork tube/triple clamp placement configuration.
Image of forks raised in triple clamps
If you have done this, raised your forks in the triple clamps, then this can account for a higher rate of wear on your front tire.
My own wear per tire looks like two rear tires for every one front. I ride my bike pretty hard and trail brake into corners VERY hard when I'm out having fun. I'm punish my ride and wring every last penny of fun I can out of it. (mind you I am very conservative on city streets) So I feel like I torture my tires as good as the next guy. Also, I don't do silly things like break stands or rip wheelies all the time to account for increased rear tire wear.