Digg has different value to different demographics. For the advertisers and business persons, it is valuable in proportion to the size of the community. To those within the community, it is valuable inversly proportional to the size of the community - unless you're in part of the community that likes videos of small children hitting grown men in the genitals with baseball bats.

The problem isn't that the community is valueless - it's that it is very difficult to monetize other people's contributions.