The LETS world seems to attract idealists who start projects which are bigger than their ability to pursue them. Focusing on software, I only know of one project with more than one person working on it - Cyclos. There seem to be several one man initiatives which aren't going anywhere. And it's not like everyone is trying to achieve the same thing either, which explains in part why these people aren't working together. Here is a list of people and projects I have direct experience of:
Some organisations I meet have a clear idea of the web sites they want, or think they do. They will write an RFP (Request For Proposal) which broadly outlines all the features of their desired web site and I think they expect that someone will walk in and build it as described. Using a modular system like Drupal it's very easy to allocate each feature to a module, and implement several features per day until the job is done.
I live and work in Geneva, the NGO capital of the world. Just in order to pay their overheads, organisations here need solid core funding. Switzerland must also have one of the highest costs of employing staff in the world. This usually means that when an NGO wants a funky web site, they can often afford to pay a commercial developer up to $1000 per person-day to build it.