How would money help?
VALVe are swimming in money.
You can´t kickstart ambition or desire to make a game.
Who cares about Valve. If there is KS campaign for HL3 what could Valve do? If they block it they will piss people who want closure. As you said they don;t care about money ether. Only thing they could do i block KS and formally announce that they are working on HL3 or let KS continue. In both cases it is win for users.
When there is no nice way to make them talk there are other ways.