To be clear, the detection here is of a mundane cosmic ray that started interacting in the upper atmosphere, but came at such an angle (and the Antarctic plateau is high enough) that the cascade it started continued into the ice.

But yes, one of the main reasons we are looking for ultra-energetic neutrinos is to try to understand the sources of high energy particles in general, as the highest energy charged particles are harder to point due to bending in magnetic fields. Measuring UHE protons from high red shifts is not possible due to the GZK mechanism, but that same mechanism will produce neutrinos that we are hoping to detect!