: It's just there to enable the story.

Right, in the case of sci-fi, it's the only way to continue telling a story 'normally' without having to deal with fundamental life concepts like the ability to communicate effectively brought on by complex physics concepts like space/time. Otherwise you have very lonely stories happening within their bubbles of feasible current-tech communicationor, else you have more current sci-fi that intends to focus on and explore scientific issues as we know it.

If sci-fi is typically an analog for current human culture, then stretching that story across vast distances where communication takes longer very much affects the type of story you can tell. Find a way to way to communicate FTL, and you can tell an analog of a story that takes place in a village, but across the galaxy, and have no communication issues.

I wouldn't say it's a 'cop out' as it were; I mean why should that be a cop out, but not the physics or tech required for the size of some of those space ships, or weapon technology, or...?

There are different types of sci-fi, and if you want to tella galaxy-sized space opera, as some kind of analog for current human culture, then you have get past the problem of communication tech. If you don't want to, then you'll be telling quite a different type of story :) (which can of course be just as good, just different)