Of course the market will care about the company's book value. It will happen when/if they manage to 'isolate and separate" the LTC business as they are trying to do.
As of their last statements on the split of the equity among their various lines of business they reported that their "margin" ( i. e. equity) in LTC was about $2.5 billion. Total equity is around $12.5 or $13 billion, so GNW has around $10 billion in equity outside of LTC. That is about $20 per share held outside of LTC.
Now imagine that sometime next year they have isolated and separated LTC from the rest of GNW. At that point the market will absolutely care about the book value of GNW, because at that point another company or even hedge fund could simply buy GNW and then split off the LTC business into a separate company and then carry out an orderly sell off of GNW's other businesses and realize most if not all of that $20 per share in equity. ( The US mi, Can mi and Au mi could likely be sold for a premium to book if a year or two was patiently spent finding the right buyer) Even if the the buyer paid $5 billion for GNW ($10 per share) they would still make another $5 billion for themselves for a couple years work in selling the pieces off. IF THEY SUCCEED IN ISOLATING AND SEPARATING LTC, THEN EVERYBODY WILL CARE ABOUT THE BOOK VALUE HERE