But I don't understand. I just started a new embark. I have my starting 7 (who were friends originally) and I also have 7 more who have joined. It's 6 months in. No tavern. I have 1 immigrant who is not on friendly terms with anyone, but who is married. I have another immigrant who is on friendly terms with every single dwarf in the fortress *and* the outpost liason. Other people are in between.
I have another fortress which is a couple of years in I guess (6 migration waves). A tavern, temple and library were build almost immediately. In this one, I started with only peasants in the starting 7. I don't know if that was the reason but they didn't start out as friends. 2 of them actually started with a grudge. But now all of the starting 7 have at least a few friends and everybody has varying degrees of familiarity down the line.
So... I'm not sure if what I'm observing is broken or not. I just take it to be slightly understand. So "friend" means "best friends for life", "friendly terms" means "people at work who I get along with", "passing acquaintances" means "people I see every day and chat with". Nothing doesn't mean I don't know them -- it just means that I don't go out of my way to talk to them. Some dwarfs are more friendly than others. There are some who have 15-20 people on their list. Sure, not facebook level, but pretty gregarious in my book. And then there are some miserable souls who hardly care about anyone. But that seems reasonable to me.
I wonder if I just have a lower level of expectation, or if other people are seeing something other than what I am.