Wrong. Accountants just don't make numbers up. For insurance companies, most assets approximate fair value and most liabilities represent expected claims. So BV is actually a very relevant number, unlike for many manufacturing companies. The problem is though, if the assets can't generate earnings, then their fair values erode and they will fall. Liabilities have to be paid. Genworth's book value problem is that investors do not see the light at the end of the tunnel (i.e. earnings), that will support the asset values on the balance sheet.
Then there also is the little problem of minimum capital required to run an insurance company at the operatiing company level ... which further causes uncertainty about the Genworth as a going concern. To me this is overblown. But....if Australia tanks and Europe tanks and MI doesn't turn around, these are real problems.
Genworth stock is like an option play. Could be zero if things don't go right, but also could make you a lot of money if world economies just stabilize or turn around. But unlike a pure option, the probablity of the upside scenario is much much higher, and priced much much better.