Second reason: You're not alone. You write renku with friends from across the street or across an ocean—you write it together. In the misty beginnings of renku in eighth century Japan, back when Nara was the capital, gentlemen and ladies of the court wrote five-line waka poems together: one of them providing the first three lines (5-7-5 syllables) and the other capping the verse with two lines (7-7 syllables). Renku emerged from love poetry and remains, today, a poetry of love.
I'm not talking about the obligatory love theme that's required by rule in every renku. I'm talking about the social act of making renku.
Love demands the sublimation of ego. To put it another way, "love" that is possessive or controlling isn't really love at all. When you truly love another person, you don't try to control them or put them in a cage. You celebrate that person's autonomy and freedom.
(renku friends)
In a renku session, participants gather in love—in its purest sense—sincerely wanting the best of the others who will contribute to the poem, willing and eager to bow to one another in a spirit of, "We are doing this, together; this poem is ours!"
This is the polar opposite of a modern, Western, egotistical poetics that says, "I'm doing this alone; this poem is mine! and, by the way, aren't I clever?"