I picked up a 1983 Yamaha virago for 700 and I have been riding it for the last 3 years with no issues. All It needed was fresh fuel and I had to clean and tune the carbs.
I also picked up a 1983 Yamaha IT 490 for 600. The IT needed a little work but it has a road title so I have it plated and I ride it to and from the trails. Both bikes are reliable and each one does what it is supposed to do with out compromising. I wouldn't want to ride a dual sport on the trails because they are heavy up top and the tires are not as aggressive. Bikes are cheap to insure and they don't take up much room so you can have more than one. why compromise when you can have the best of both for less than a car.
The street bike is outfitted with heated grips a windshield and I have added a plug for a heated vest. I can comfortably ride when the temps are in the teens. As long as I have traction I ride the bike even in the winter between snowstorms when the roads clear.
Isn't that IT a big huge 2 stroke bike? Yamaha had a YZ490 as well that was a scary bike.
I wish I had some pictures available but you can very easily convert a decent factory dual sport bike into a mean off-road machine. Weight can be removed or moved and there are street legal knobbies that are very aggressive. I even chose to use the DOT legal knobbies on my last off-road only bike since they were so dang effective and tough. (Tires are the Dunlop D606 series)
So to the extreme there are street bikes like crotch rockets and then there are off-road race bikes like say a two stroke kick only no lights bike. There is a huge middle ground and lots of overlap for most riders. I desert race my dual sport and will be doing the annual 100 mile desert100 in two weeks. I fly by many high dollar dedicated off-road bikes with my street legal dual sport.
It's not the bike, it's the rider. I have been spanked by crazy 50-60 year olds too. Those old guys are nuts, lots of broken bones in their history.