It is actually possible to control your character while in air. It's just very subtle to allow you to correct jumps over longer distances.
Balancing the air control was a bit tricky. Previously you had much greater control in the air but i soon discovered that this introduced an exploit in the game which a player could easily take advantage of. (Basically it was possible to do a wallrun, jump off the wall and strafe back to the same wall while being in air and doing a walljump again and gaining height while doing so.)
So i reduced the air control to make this exploit impossible but give the player still enough room to correct his/her jumps.