Presumably, the reason they're implementing commands to switch linkshells vs directly inputting text into those unequipped linkshells is the amount of time and work it would take to do each.

Right now functionality to switch between linkshells already exists abstractly, it's just that those functions can only be accessed through the user interface. In order to create a text command to access those same functions, the workload is tiny, they're just implementing a new text command that will run an existing function.

On the other hand, being able to type directly into other linkshells would ostensibly require significantly more work, but is hopefully on the table for 2.0, though having a "next linkshell" macro or built in hot-key is a significant improvement on its own, and a perfectly reasonable one unless you're talking in half a dozen LS simultaneously.