Epistemologically, if you spend all of your time analyzing a discourse without reference to the original subject of the discourse, you run the risk of remaining so highly abstracted from the subject of study that you get not closer to the truth, not closer to reality, but further away from it. This of course presupposes that you believe in such a thing as “reality”. An alternative point of view denies that there is such a thing as “reality”, or at least denies it is possible to know such a thing. In that world, all there is are discourses, and any one discourse is just a serviceable as any other discourse. But reality has a curious way of continually reasserting itself.
The fellow who asserts that there is no such thing as ultimate truth should ask himself about his own statement.