Were deconstruction simply a lie we would have an easier time combating it. But it has its points, and those who hold these points run into a problem like the men in the legend: they see only deconstruction. Further, they also have a problem that is quite rife in modern academia: the disregarded middle. To put it simply, it is easiest and clearest to argue black or white on any issue, rather than grey. It is easiest to argue all or nothing, rather than some. As soon as the question of "some" arrives, it is almost immediately followed by "how much?" and "Where do we draw the line?" These questions are difficult to answer, difficult to uphold and nearly impossible to defend. So the modern academic very often pretends these questions does not exist. Therefore, only the extreme is reality. Anything in between is discarded. The problem is, the extreme is often absurd. You can find yourself arguing, with all seriousness, that an elephant is a large plant. Even more absurd, you may find yourself wondering how you can argue against someone who believes, in all seriousness, that an elephant is a large plant.And yes, they are so confused they will actually believe their own twisted rational.
And if you think I am kidding, just visit a few sites dedicated to either fringe. It won't take long to find the lost skill of debate missing.