Let me go ahead and start off with the mandatory disclaimer: I love the death out of this game. The five dollars I spent back in the 0.3 days keep repaying themselves, and I could see myself spending the current 10 bucks, or even 20 bucks on release, on getting it. I've replayed the game dozens of times, investing hours, DAYS even, per playthrough.
... But therein lies the crux. See, that's just it: I feel like the game just sort of loses its drive once I've reached a certain point in my playthrough, usually by the time I'm rolling in a capital ship, am floating around level 20-30, and can indiscriminately wipe out anything and everything I see. With the help of mods, at first, and later the hyperspace/'more than one system' update, I found myself able to explore a bigger universe, and even before Alex and Co. implemented the current faction system, I played the hell out of loadsafaction mods like Exerelin, Corvus's series, and SS+.
Every time, vanilla or modded, my playthrough is more or less the same: Pick a faction who I want to be best friends with this playthrough, and do whatever I can to curry favor with them. Build up rep till I'm representing them in style with a full fleet of homogeneous warships, with the odd plundered vessel from a different faction in my fleet's numbers, and then... lose interest as the game rapidly becomes a chore of chasing down enemy battlegroups, wiping the map with them, running back to the nearest station to offload my loot for money I don't need anymore.
But even when there's a dozen+ factions on the playing field, wherein I feel like there's active conflict and I have an effect on politics in the relationship, I can't help but feel the tedium get to me before too long, usually around the 15-20 hour mark for even the most heavily-modded playthroughs. And I find myself worrying, because while, yes, I very much enjoy every time I start a new campaign, I feel like the game will never be anything more than just a bunch of these start-from-scratch replays.
This is by no means a dig at the dev team -- I've no better ideas how to make some sort of lasting endgame. Perhaps you have things in mind for .7, .8, .9, the final release, and future updates. I simply don't know. But I'd just like to know if I'm the only person who more or less just lives for mods coming out, hoping something comes out that breaks the tedium, be it a faction with a bunch of new ships and weapons to find and collect, minor gameplay mods that tweak the base structure of the campaign (i.e. SS+ adding new skills, the Assassination missions, etc.), or completely overhaul everything, adding new features along the way (i.e. Ironclads, or the quickly-evolving EVE TC).
Although it's indicative of a guilty conscience to repeat this fact, I'd like to just emphasize that I am absolutely not criticizing the game. Perhaps lack of endgame is a known issue, or maybe it was always intended to be played with short little campaigns that you don't have to invest weeks of playtime to really complete. I don't know, but it's just something that's been grating on me.