FFF - I agree, most reasonably powerful aircraft need a little more room to stop than to go but beware sweeping generalisations (eh 540!).
I can usually stop a Bonanza really short mainly due to gear geometry and the way the wing flies on the back side of the drag curve (ok 540 so there is a use). Getting airborne is another matter entirely due to the climb gradient decrement that is unavoidable if one tries a soft field style take off. Not a problem if you have a reasonable climb out area in terms of obstacles. This technique is very useful in cases of rough or very wet fields (not just short places). I find that the 114 is very similar.
Single Comanche or SF260 are the other way around since the geometry and drag characteristics makes this sort of approach impracticable.
In either case proficiency in that regime is needed.
540 can't see the point of any of the above.
540 - I have other ideas about why people give up. Nearly all of it is down to cost and motivation. I think managed groups and a scheme of mentoring would help greatly (I have developed some plans for both) but I agree that the 45hr PPL course casts the average pilot adrift at the end of it.
Bear in mind, however, that not everybodies idea of Valhalla is to be adjusting the V/S control on a mode control panel.