i think the hack was done just to prove the site is vulnerable.

I agree, however hacking a site that never claimed not to be vulnerable is a bit... pointless.

From Fausty's comment on wired:

Yay, how brave and skillful to “hack” something that’s already public, provided for free, and supported by volunteers.

"programmers passwords?" No, guys, just Monks passwords, for a site which runs http, that obviously stores passwords in plain text ("mail me my password"). Geez...