I have a little over 1000hrs C210 in the Top end, in and out of all types of strips in both line and training ops. Stall warning on take off was only heard in hot turbulent conditions and only very short blips as the airflow over the stall warning messed about close to the ground.
As any 210 driver will tell you, it is a very capable machine able to haul loads out of short, sh1t strips in almost all weather, IF you fly it right.
Full load, up hill on a warm day? This is not the decision an experienced 210 driver would make. Better to take 5kt downwind down hill than try to wrestle it off the ground up hill racing the tree line to the sky.
Poor decision by the pilot and if "it happens all the time" I suggest it's time for tea, bikkies and more icus!