Why are you giving him such a hard time over a nomenclature issue? It's obvious he was building an Aurora 'generation ship', not an IRL one. Loads of people have done this thought experiment before. Not my cup of tea but there's hardly any reason to get your knickers in a twist over the details either. Let's take a breather and figure out how to be civilized and friendly in this ultra-niche corner of the Internet that we inhabit.
Also, WORDS HAVE MEANING.
Generation ships are ships that fly from one star to another at sublight, and take generations to get there. Thus the name. Also, the fuel requirement.
It's worth noting that while words do have meaning, the meaning of words is hardly fixed an immutable, and meaning is as a rule context-dependent.
To wit: in the context of Aurora, a game with jump points connecting stars, a "generation ship" need not be capable of traversing light years of distance between stars (with the attendant requirements for fuel capacity, life support, etc.). Usually, the idea of an "Aurora generation ship" is to support a broader idea of nomadic gameplay, which OP described:
wasn't really going for a IRL Generation ship but more of an in game one, where rather then settling worlds would go from one to the next mining resources and expanding the fleet kind of thing
This is a concept which, as Garfunkel noted, people have explored before on these forums - though not very often, and as a new poster it's entirely understandable if you're unfamiliar with that admittedly Aurora-specific meaning for the term.
That being said, it also doesn't really help anyone to nitpick about the meaning of words unless the meaning is genuinely unclear, and inquiring for the sake of clarity hardly requires a follow-up to argue about whether or not a term is appropriate nomenclature. Said another way: Aurora is a game that heavily caters to roleplay, so different players tend to use the same words to mean different things (and, for that matter, different words to mean the same thing). Another example: Steve himself uses "lascannon" to denote twin railguns in his WH40K settings; it would hardly be worth anyone's time and effort to chastise Steve on the grounds that "lascannon" should properly and only refer to a weapon which is of in-game laser type.
I believe this is what Garfunkel was, perhaps a tab brusquely, intending to convey. The "culture" of this forum, such as it is, is one where we generally refrain from arguing points of pedantry (save when some greater import beyond nomenclature or the number of significant digits is to be had from doing so) as a concession to both roleplay and the fact that many of our community members have adopted English as their second, third, etc. language.
I do apologize if this comment, in turn, comes off as slightly pedantic and/or patronizing. I am choosing to give the benefit of the doubt here and explain as best I can some things which might be unfamiliar to a new member - you certainly would not be the first person to join this forum being used to the standards in other corners of the Internet and run afoul of those implicit norms we hold dear.
That being said:
I made a bit of a backhanded complement
I might suggest that there's rarely a good reason to issue a compliment with the backhand still attached, unless a degree of offense is intended (which is to say, not generally).
because I said "umm, actually".
I might make the observation that, even well beyond this forum, folks who make a habit of saying "umm, actually" tend to be not well-received by most others. This is, I stress, only an observation.
And yes I'm being a bit impolite to you, as you have been to me.
Finally, I would gently suggest that responding "like-for-like" is rarely productive. Since we, as humans, tend to perceive the words and actions of others as more offensive than intended, responding "like-for-like" tends to promote escalation of tempers, so that it is usually more productive to intentionally de-escalate so far as possible.
I hope this is helpful and perhaps clarifies some things that were perhaps not immediately apparent to a new forum member.
I'm kinda offended by your made-up white knight proxy offense, btw. If we're going to play that 
