I understand what the hook does specifically. Sorry for not being very clear.
I want to understand what the intention was – what I mean is WHY would I use it? I ask b/c I initially was attempting to extend Views to have some additional settings on this page and thought I would be able to use it to save ADDITIONAL settings. But I haven't found a way to really do that yet. So it seems this hook is just to modify the current settings without a UI. Any additional insight how to extend the Views admin is also greatly appreciated.