While it would definitely be useful in some situations, it would also have some scaling issues. If you look at the density of potential destinations closer to the core, e.g., around Colonia, you'd rapidly end up with a massive clutter of destinations, and the chance of seeing a system you'd want to target diminishes rapidly.
There has been talk about making bookmarked systems somehow available in the navigation menu (with the caveat that it's currently not possible to plot routes outside the galaxy map for technical reasons), maybe having those visible in the targeting overlay as a much more controlled element could be a more universally applicable thing.