> Releasing their source does not imply that they are providing a working turn-key product that another company or individual could just one click install and have Digg back.

Except that exactly what most people will want and get mad if it's not easy to run. The backlash from that isn't worth it.

> I just feel that this is not a barrier for open-sourcing their product.

IP alone can be a bitch and that coupled with the fact that a number of companies have secrets (key/tokens/passwords/etc) in their code and cleaning those out (AND removing the git/svn history) is no small task. Lastly there are number of open source RSS readers out there, I seriously doubt Digg was doing anything particularly innovative in this space and I don't imagine many people care to build on something they made 5 years ago and probably didn't update much since then. Especially if it's not built with the "New hotness".