The interpretation of some of Heidegger's statements as incoherent isn't just something his enemies came up with; it is supported by other statements of Heidegger's (as Carnap notes in his criticism of Heidegger). I really am curious as to what coherent statement you think you can find in "the nothing itself nots."
Ok, so the statement is made as part of a mission to say something intelligent about noumenon. In other words, Heidegger is trying to say something about what things are, totally independent of our perception of them. As I alluded above, I think trying to grapple with perception-independent-thingness is . . . not a good use of one's time.
Anyway, Heidegger does lots of deep thinking about this problem, and ultimately says that there is "Nothing" as the basic characteristic of objects. To me, that's a plausible response to it's turtles all the ...
[I'd put this in an open thread, but those don’t seem to happen these days, and while this is a quote it isn't a Rationality Quote.]
— Geoffrey K. Pullum, Language Log, “Never fails: semantic over-achievers”, December 1, 2011
This seems like it might lead to something interesting to say about the design of minds and the usefulness of generalization/abstraction, or perhaps just a good sound bite.