I didn't read the whole thread, just the original post
Unfortunately when someone does something cool, every other yokel will want to do it too. Before you know it the coolness is gone.
This shouldn't bother the 'real adventure biker' though. If you started with DS biking because you love the outdoors and you love bikes and NOT because you wanted to look cool then there is no reason why you shouldn't continue long after the 'fad' has worn off.
The difference between 4x4 and Adventure biking is that every asshole can get behind the wheel of a car and push over some trees in a neighbouring country. Not everyone has the guts and the determination ride a bike for hundreds of km through tough terrain.
The DS market may be growing but it also has the largest customer turnover. There is a shocking amount of low mileage second-hand DS bikes available because people like the idea of adventure riding but they just can't hack it for more than a year or two. They lose interest and move on to boats, quads, kite-surfing, etc.
As for the hooligans messing it up for the rest of us; there is nothing you can do about it short of personal intervention. When you see guys doing something wrong, go up to them and tell them to stop. If you are too scared, tough. If you report them to the authorities, don't be surprised if a bike-ban follows, tough.