Of course there is use to share data between worlds, that's just silly. You think because they can't IM there is no use for communication. GO HOME YOUR DRUNK!

You don't have to send humans in big ships, you can send tiny ground based laser powered probes that setup a receiving station and then beam the human mind as data that can go the speed of light. None of that put you up against the fundamental forces of the universe like trying to carry enough fuel and food to bring humans through space or pretending you can keep human in stasis for thousands of years and not have them turn to mush.