As frustrating as it may be, there must be reasons for what seems like Mark's madness, like "industrial espionage" or sharing too much information with competitors or even jealous enemies.
Apple is famous for being very quiet about potentially very BIG things. And Amazon is also pretty secretive too, mostly for competitive reasons. Employees in both companies are probably scared to tell anyone outside of the company anything because they're afraid of losing their jobs. Google is another one. The secrecy hasn't hurt the shareholders in any way.