I think FOSS really only works well for infrastructure type of projects, things where the customers are downstream programmers or at the very least very technic

I think FOSS really only works well for infrastructure type of projects, things where the customers are downstream programmers or at the very least very technical sysadmin types and power users who can understand the gory details to some reasonable depth. Those projects work because they are centered around proven abstractions that are broadly applicable, thus allowing for a tight charter and some stability in requirements. End user software by comparison, has not really been successful in the FOSS model. There have been many attempts, but they perenially lag behind commercial offerings, and thus primarily see adoption from the ideologically motivated and/or very cost sensitive users.