I would have assumed that anyone would recognise that quote without having to look it up. It's an interesting generational demarkation I think.
"But the way we idealize the communitarian ideals of the past and their impact is mostly nostalgia "
Not true.
Or rather ... of course we always make the past into 'nostalgia' but there's absolutely decrease in civic participation by almost all measures.
- Participation in local community groups is way down.
- Voting participation is way down.
- Direct political participation and Union memberships are way down.
- Millenials are the first generation in modern times to not consider 'hard work' (which is a kind of contribution) as top 5 'important value' (Greatest, Silent, Baby Boomer, Gen X - all had this as a top 5 value).
Now - we can definitely argue the value of 'community groups, classical political causes and definitely 'self described virtues' ... but it's definitely directional.
At very least it's a function of opportunity: people just have so many choices, young people can literally do anything. Three generations ago one's scope of choice was extremely limited.
People can now chose to participate in a 'political meme' on Twitter instead of joining the local cause. There are obviously many advantages to this, but disadvantages as well, as there is generally less materiality to Twitter wars. That said, when 1/2 nation Tweets, things can change.
Here's literally Google's 'ngram' viewer for the word 'duty' [1]
I don't need external evidence for this because in my own family I have very extended generations and I knew my grandparents generation very well: they were very coherent at the local level. My grandmother knew everyone on the street and must have helped or attended with literally over 100 weddings as it was the 'local ladies groups' that usually catered weddings -> for free (!) back in the day. Among other things. And yes, it was 'ladies' who made sanwiches, never the men.
The clubs my parents belong to are having a hard time attracting members's children into memberships which they have done for generations.
I would go so far as to say the level of local, social cohesion and the hyper local social networks were so strong and specific, that we can't read someone like Mill without understanding it.
The comparison between my grandparents youth, and suburbian 'placelessness' today wherein there aren't really any cultural demarcation points or locally established 'social rules' Mill references ... is really shocking, and that's only across several decades.
[1] https://books.google.com/ngrams/graph?content=duty&year_star...