Frankly, I resent the implication. After all, if you behave in a manner worthy of respect, you're likely to be welcomed back when you return. However, I reckon serious off-roaders would agree that such problems are caused by ignorance. Let's take the obvious temptation to over-rev your vehicle to conquer an obstacle. The resulting uncontrolled wheelspin can cause tremendous damage on paths and beaches, with the ruts left behind creating potential watercourses that rapidly erode.
Erosion means no plants, and it's the plants that bond the soil.
Then we get the cowboys who indulge in a touch of uncontrolled beach driving, and the behaviour of motorists on beaches and dunes in general. This includes the way these types behave in campsites at night. Loud parties are not necessarily a true reflection of the off-roader's character, and let's face it, it's long accepted now that alcohol and driving make a rough combination, whether on the highway or the beach. Good news on this score is that an increasing number of beaches are now advocating a permit system which will govern the use of vehicles on the beach and the behaviour of their drivers. While on the subject of driving in sensitive areas, it's always best to obtain information and guidelines about the area you intend driving in before rushing in on all fours.