Henderson says that Multivac is no better than the data fed into it. What does he mean?

Henderson tells Swift and Jablonsky that the data used to program the super computer Multivac, which supposedly provides the title of story, had increasingly become "unreliable" and "meaningless." The data used came from several different sources and was often impossible to consolidate. The data also went through the filters of the men who programmed the computer who "had their own skins to think of and competitors to stab." The data which came from the planet Titan was "delayed" and "would introduce an unexpected bias." Since Henderson could not rely on the data, he "corrected" it through "intuition." In other words, the data was based on Henderson's totally subjective ideas and not really based in science. Thus, the war that was presumably won by technology was actually successful because Henderson, Swift, and Jablonsky guessed correctly. Jablonsky even admits he didn't use educated guesses, but rather flipped a coin for most of the important decisions.