Can you please explain 'dumb'?

A: I think we lost him!

B: Our junk sure is dumb.

Tara2Can you please explain 'dumb'?

There is not enough context. It sounds like the speaker is using the word as a sort of meaningless blanket condemnation, but I don't know what their "junk" is or what it has to do with their escape, so it's hard to say..