The paper's title refers to the Web having been implemented by those outside the systems research community, who had elegant solutions to interesting problems but didn't pay enough attention to needs of users. The authors are afraid this might happen again if P2P researchers ignore the needs of Grid users. The third generation P2P infrastructures represented by systems such as Tapestry, Pastry, and Chord are amazing. For example, with one of these, you could implement a truly distributed DNS system that doesn't use hierarchy or centralization, and thus would be much more immune to DoS attacks than the current system. P2P researchers should heed the Call to Action at the end of this paper.
Karl's version of Parkinson's Law: Work expands to exceed the time alloted it.