There are a number of reasons why the ability to select links is desirable.
1 - it would allow you to delete individual links without having to delete ALL links going into a node’s pin / exe.
2 - once the link is selected there could be a key command that would re-wire it to a new port you are hovering over.
3 - again with the link selected, there could be a key command to copy the link and wire that to the port you are hovering over.
etc etc. I’ve used other visual scripting programs that have this functionality and I’ve found it to be very helpful.