As an urban designer I agree 100% with your findings. There was a similar successful scheme in Miritini, Mombasa City, Kenya. Today it is a built up vibrant , mixeduse community where more than 20 years there was only empty serviced land. It was an organic growth that was homegrown and driven by both local and wide consumer demand. Sadly World Bank seems to have forgotten all about site ad services and is now preaching affordable homes as engines for economic growth. Any affordable housing business model should include site and services as one of its tactics of delivery.