Dear Rebecca Drouilhet aka whitedove,
I'd say a lot of people do/write/read/perform for different reasons.
Some do it for a leisurely hobby to fill up time, some pursue as serious amateurs, and gain publication credits, others to interact with others if they are housebound (not uncommon) or not able to work for other reasons.
Paul Reps attracted tens of thousands of people, Richard Wright did haiku as he was dying and not so able to write his incredible novels and other great works.
Some Japanese women did it to rebel against police gas attacks against them because of their gender in mid-20th century Japan.
Others were imprisoned, and tortured to death for their beliefs expounded in non 5/7/5-on haiku.
The list goes on.
The current President of the EU writes haiku for pleasure, and as something relaxing, sometimes directed to himself in self-mockery. He writes good haiku in his native language but alas his publisher insisted on doing the bad translations himself.
I don't know how well Westerners can do special occasion verses as haiku, but I've seen verses that are called haiku on various greeting cards, and Hallmark own a copyright on certain ELtranslations on Basho in particular.
You said:"Haiku could function as a social tool for greeting one another..."
Of course a call and respond activity is renga or renku which is gaining ground again in Japan and highly popular in the West at present.
"...for use in diplomatic relations and as gaming, fun and entertainment."
I'm not aware of its uses for gambling, legal or otherwise, so you'll need to enlighten me although I'm not particularly into gambling.
You ask:"My question for discussion is do you think haiku has pragmatic functions or work to do as it interfaces with society?"
I'm not sure what you personally mean, so I can only speak for myself. I run haiku, and renga or renku courses, and activities, both as a professional poet, and someone involved with haikai literature for 20 years, for the general public; creative and non-creatives; people in prison or mental health institutions; and at festivals or other organised events.
The quotes/comments I get show that haiku and other haikai activities have meant a lot to them in their personal development as humans, as well as writers, or would-be writers.
Although I'm a jobbing poet who does this for money, I absolutely enjoy the job, and put more into it than I am paid to do, and would not do it if I didn't learn something myself along the way.
You also say:"I am also curious about whether or not poets use haiku in their community/family settings to commemorate special events or occaisons."
I did run haiku, tanka, and renga weekends for the Deaf Community, both the public, as well as DeafPoets, and we did create, IMHO, the world's first BSLrenga. The first weekend of workshops and theatre performances were as part of a challenge to prove that (British) Sign Language was in fact an official language if able to be composed in authentic haiku, so it was a special occasion, but also to answer a challenge by a scientist.
I do work with families, directly, or indirectly, with haiku and renga workshops/activities at institutions or festivals, but not geared to specific celebrations such as birthdays or weddings.
Also I did compose a specific ballad in Queensland which did prevent a fight between the bride's and bridegroom's parties. :-)
I think others might better answer your questions and I will be intrigued as to how they address this aspect which is very Japanese, and not easily transferred to English Language haiku or haikai verses.
This past week during a second reading of Patricia Donegan's book, Chiyo-Ni: Woman Haiku Master, I noticed that Patricia commented on the social work that haiku did during Chiyo-Ni's age. Haiku could function as a social tool for greeting one another, for use in diplomatic relations and as gaming, fun and entertainment. I compose haiku for special occaisons such as weddings, births, special days and so on. One poet I know recently mentioned that after she was approached by an acquaintance who wanted more of her poetry, she composed poems for the woman to meet her needs. My question for discussion is do you think haiku has pragmatic functions or work to do as it interfaces with society? I am also curious about whether or not poets use haiku in their community/family settings to commemorate special events or occaisons.