This has simply not been true for me. I participated in DV lottery for quite a few years, and later on had multiple visits to US Embassy and never have had any

This has simply not been true for me. I participated in DV lottery for quite a few years, and later on had multiple visits to US Embassy and never have had any kind of problems with getting my visas approved whatsoever. I think your friend might be having some other issues, not the DV lottery.