There are plenty of things for which the results of single-threaded benchmarks are completely irrelevant, like the compilation of a big software project.

There are also things that are well-correlated with the single-threaded Geekbench result, like how responsive will appear an Internet browser, but for many professional uses the multi-threaded performance is much more important than the single-threaded performance.

For many CPUs, and depending on the computers in which they are installed, the single-threaded and multi-threaded results are completely uncorrelated, because during the multi-threaded benchmark the clock frequency in some computer may drop even 4 times (there are Intel CPUs with a so big ratio between the maximum turbo frequency and the base frequency), while in another computer it might drop only by 20%.