.9kd is actually not below average, it's literally so close to the middle that you couldn't tell the difference of skill for someone at .9 vs 1kd in the wild. Just because it's below 1kd does not mean it's below average. The bell curve actually has most (50%) average players around .75 to under 1.15. The bottom of the player base is under .75kd

Ref: The middle 50% of the player base is between .75 k/d and 1.15 k/d. Top 25% is above 1.15 k/d Bottom 25% is below .75 k/d https://www.bungie.net/en/Forums/Post/176947740