The creator had an entire society dedicated to these little shits, but not in any constructive way. A low autism way to say it is he tried to write the Silmarillion, but forgot the only reason anyone gave a shit about a dictionary of a fiction world was because people already cared about that world through the books.
This is actually shockingly common in the furfag sphere. Including the Avali, I can think of three 'popular' races that are made up wholecloth, but accepted amongst the furries more than actual animals sometimes. All of them with richly detailed backgrounds and lore, but absolutely no actual heart behind any of them. Because all of the writing was clearly meant to make them just fetish bait. In the Avali's defense, I don't THINK these guys (or their culture) was made for the creators dick, but it still wasn't all that well thought out. But I digress.
Furries saw these adorable little fuckers, instantly tried to make them horny, and proceeded to ignore every puzzle piece in the mod makers box, because they wanted their Avali to have big tits, and/or be a playboy running around the galaxy fucking everything he saw. The dev saw this, lost his speghetti, and essentially started a tism war with the furries, culminating in, IIRC, him stopping working on the mod, taking his ball, and going home, leaving the Avali half developed as the game continued getting updates.
This spilled over into the official forums, which were already a hotbed of retardation (don't look up how Floran breed. Spare yourself.) resulting in the rest of the fan-base wanting to leave just to avoid the stigma of being associated with players like that. Mix that with an abysmal launch, general burn-out, other mod tism fits, and already being pretty niche? Starbound was fucked.