I'll preface this by saying that you have your preferences, and things you want to do within the game. The game itself has changed enough to warrant you saying that it's not worth coming back to. Fair enough.
Now for my response to your post:
The game is a roleplay server, not a PVP one. The entirety of your post talks about being most efficient with guns and associated components (ship classes and power cores). What ruffles my feathers a bit is why people consider PVP / PVE the only thing to do in this game? I would imagine that a reasonable person would simply try something else if what they came back to is somewhat unrecognizable.
This next point may have been pointed out by another community member from another similar thread. When coming back, you are comparing the game as it was when you last played to how it is now. These differences cause frustration because it's balance is now significantly different. Effectively it's a game you now have to re-learn. Or, as previously stated, instead of relearning, try out another aspect of roleplay.
I can respect you leaving for your own reasons (if you say, hard to tell), though do be mindful that as a former(?) community member, you are also in the position to strengthen interactions and events by doing what you can to make them better. I see too many get discouraged by the same reasons you mentioned in your post.
