the longer chassis helps to keep the front end planted. less wheelies, and less front end push in corners. It also spaces out the wheels so there is more time between the front hitting a bump and the rear hitting the same bump. this allows the rig to settle down, and makes it more stable.
a shorter chassis will corner sharper, but the rear end will step out easier as well.
a longer chassis will not corner as sharp, but you can take the corners faster without spinning out.
It has nothing to do with space available to work on the vehicle.