All true, but as I understand it (and I'm a late comer, so my experience is limited), Fritzing started out as a funded university research project so there may actually be more documentation than has been released. When the funding ran out it got converted in to an open source project I think (based mostly on the paid parts creation service that is available) hoped to be funded by parts creation for some of the commercial vendors (thus the lack of parts creation documentation) as well parts editor isn't yet completed so its possible they were waiting for that to complete before documenting and then funding ran out. There appears (at least to me) to be a good and far reaching plan of how development should have proceeded, but funding died and my sense is that not as much funding as hoped for is coming in from open source and time on the developers part is now lacking (likely because of having to fight for funding for new research projects at the day job). If we want to see Fritizing continue, its up to us to help out documenting what we can and possibly trying to fix bugs in the source (although I'm finding just parts creation to be a challenge 
). The part that is here is pretty amazing even in its incomplete and somewhat buggy state. With enough effort you can usually work around the bugs to get it to do something useful to you (at least I can) and the source is available to make it better if you can, both good things as far as I'm concerned.
Peter