I don't understand how code with a bsd license without a patent grant is better for the apache foundation than facebook's bsd + patent license. With the former,

I don't understand how code with a bsd license without a patent grant is better for the apache foundation than facebook's bsd + patent license. With the former, the entity donating the source can sue you for patent infringement at any time. Clearly the apache 2 license would be preferable (and what rocks db did), but I am puzzled the foundation accepts bsd code in their products, given their worry about patents.