Powerful memoir by Mai Donohue that somehow had to be self-published - why?

Been reading a self-published memoir by friend Mai Donohue, Crossing the Bamboo Bridge: Memoir of a Bad-Luck Girl, and I'm actually startled that this book was not picked up by a commercial publisher, as it seems to have everything going for it: a terrific personal narrative of a woman who overcame incredible adversity to emigrate to the U.S. and build a life w/ a terrific family and contribute to her community in many ways. Mai was born in rural South Vietnam about 70 years ago and lived her entire youth amid various wars - which she recounts from the point of view of a villager. Death happened all the time, and the villagers were continuously threatened and intimidated by the rival forces, Viet Minh and Viet Cong (the latter come off as smarter and more humane). But this isn't a political narrative, it's a personal narrative that is both unique in its particulars but universal in what many women, especially 3rd-world women and girls, experience and endure (to this day). Mai, despite her obvious intelligence and ambition (she hoped to become a school teacher) was pulled from school, engaged against her will to an unpleasant "first son" from a nearby village, and she endured beatings and humiliation in her early married years until she was brave enough to go off on her own and escape to Saigon (leaving a sickly son behind). The journey by bus to Saigon is in itself worth reading. That's about as far as I've gone to the this point, but knowing Mai's story, as so many in this town do, we know she met an American naval officer, fell in love, married, became a U.S. citizen, and has had a long career in education in the U.S. Book is from Stillerwater River press.