And what platitude could you possibly offer to the guy who watched the final extermination of his entire species as a retort?
David's going to go on about how honor matters on a metaphysical level or something.
It's why he hates Javik so much. Minus his prejudices, Javik is pretty much what Shepard is to the Protheans. Before David says Javik failed because he wasn't 'heroic' or 'honorable' or some bullcrap, Javik fails because he was born when the Reaper extermination of the Protheans had been ongoing for several centuries. But of course, that should't matter to a sufficiently heroic and powerful character. Nevermind economics, lack of resources, or any kind of strategic capability, since those aren't really 'powerful'.