Irulan,
I agree, you certainly CAN use road bikes on dusty trails. And, yes, MTB components will gunk up just as quickly. I don't know if they are made to take on worse conditions than road components........ I would like to think so. I guess it's just my take on it. I imagine my mtb as a tougher bike and my road bike as more delicate. I also treasure my road bike a bit more, being more of a road than off-road rider. So, just because I wouldn't want to take my "baby" (road bike) on a trail ride doesn't mean that it's not the right thing for someone else. If my post came across that way, I wasn't stating what I meant very well......... I'm glad someone jumped in with another POV. We're all different riders and need to ride what works out best for us. We have these bikes to RIDE, not to sit somewhere and be admired. Enojoy the ride!
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived." Captain Jean Luc Picard