No, and I doubt it's as high as 5%, but does it matter?
Lots of people use dmoz. Lots of people would miss it if it no longer existed. That's my point.
The OP's point is that he feels the SE's should not give weight to it or its clones. That's a separate issue.
But let's not knock dmoz for the wrong reasons - it is, and can continue to be, a useful resource. The amount of people using it, and the overall benefit to the internet community, is irrelevant, unless you're footing the hosting bills for it.