I bet there have been lots of cases of flight into terrain in what would have been legal VMC, 3000m or 1500m (take your pick of the particular license privileges).
The most common fatal scud running situation probably is an entry into IMC but it's equally easy to get snookered into a no-way-out situation where there are hills all around. Add heavy rain or dense drizzle and there is little or no forward visibility, and bang! I guess this is why the FAA have the chandelle in the CPL - it's the ultimate way out of something like that.
The other day I flew a circling approach into a south coast airport, perfectly accurately I reckon, but with the GPWS going berserk (at least "she" has a nice voice) due to proximity of terrain, and I would never want to do this in rain.
Nice to have met you too Broomstick
On the main subject, this one will run and run.
At one end, we have the usual suspects, intimately familiar with their local area right down to knowing every sheep by her first name, and they can't see any reason for teaching anything beyond DR. Most of them never go very far. A few (very few) highly motivated (and I dare say way above average experienced and skilled) specimens have managed some really epic trips, and this is repeatedly used to support the argument that "you can go around the world with just a compass" etc.
At the other end, we have hundreds of major CAS busts every year, done by a fair cross-section of pilots. On top of that, we have many more pilots getting lost in a pretty decisive manner. Given that most new PPL holders chuck it in right more or less away, the cross-section of these people will include both newbies and old timers and everything in between.
The fact is that DR fails to deliver the goods for the average pilot. Unfortunately this cannot be ignored because it is driving the regulatory pressure (mandatory Mode S etc).
In between the two, we have the average new PPL who is holding his piece of paper and is wondering what the hell he can do with it. It's a bit of a scary prospect. Stories of Euro 10,000 fines in France... He will have heard of GPS but doesn't dare use the 3-letter word in front of his instructor. GPS usage remains a mystery for many, with bollox scare stories about how you can get lost by pressing the wrong button, etc.
I don't see how GPS can be incorporated into PPL training without making installation mandatory in at least one plane per school, which they will resist fiercely.
My guess is that say 10-20 years hence, when most of today's spamcan fleet has been scrapped, GPS will be common in the training fleet and this will enable the modernisation.