So are you saying that because someone has been stalking for years that he obviously knows more than someone who's only done it for one year? I find that to be a very blinkered view. You may not have a clue about diseases or even open and closed seasons but if you eat the venison yourself and never get seen shooting the wrong deer then who is to know that you're clueless? Passing any course is written proof that you have got enough of an idea to pass. No more, no less, but don't knock those that bothered. Without the certificate it's pure and simple speculation as to whether you know anything at all!
I have yet to read or hear of any newly qualified DSC1 stalkers taking 300 yard head shots either and yet because they're newly qualified you assume that they must be numpties who are doing such things? Well excuse me but some will be looking at the spelling in your post and be thinking that it's not them who are the numpties!
Finally, have you considered that the reason why nearly everyone passes the DSC1 is because the standard of instruction being put on by the professionals is so good? I am yet to read on here about a training body who made a poor job of it? Just my thoughts and I await the incoming from the so called 'experts' with interest.
PS. I have a friend who has been playing football for 35 years. Still got two left feet though! An expert he most definately isn't!