For me it's been like a splash of cold water to the face, remembering just how fucked up 
tier liberal takes were, are, and will likely continue to be.
I'm sure there's downsides to complacency, but it was nice having some ground assumptions when going into a thread, like "society can and should be improved somewhat" or "the ruling class acts in its own immediate self interests and any other claims regarding their motivations are propagandized lies" or "climate change is real, it's bad, and it's getting worse," or more trivial stuff like "Tesla cars aren't good."
I'm sure potential comrades are out there and while it really is necessary to reach out to more people at some point (offline too, orgs especially, but while we're here, you know?), it's been sobering to realize just how far rightward mainstream "progressive" liberal thought really is on average. 
We have to interact with people outside our little comm at some point if we don't want it to die a slow death of attrition. Many, maybe even most people will be unreachable, but we were able to cultivate a sizable userbase back on Reddit just by being uncompromisingly left and very active. There's for sure a lot of trash on Lemmy, but it's not worse than Reddit, and I think ultimately, we will get new comrades out of this.
I respectfully disagree. The site culture pre-federation was unlike anything else, anywhere else. There was no other trough for that brand of slop. We wouldn't have died, but it just wouldn't grow very fast or change very much over the years. We have still, fortunately, maintained most of that site culture, but it will never be as chill and friendly as it was. So far it's been fine, but none of the other sites (sans Lemmygrad) have basically anything interesting to say that isn't just said on Reddit or 4chan.
I think some of the more interesting users are somewhat invisible because they're setting up here and using hexbear as their home instance. I've seen a lot of new usernames in the past week.