Why use net for something that isn't a NETWORK????????
(no adequate rolleyes smiley)
Obviously, all of this is keyword dependent. The fact is, .org is a broadly accepted TLD that conveys meaning and purpose when coupled with a synergistic keyword.
.net is simply the second choice that people use when the .com is taken.
People remember and accept .org for what it is.
They don't do that with .net.
No more than .net isn't limited to networks, .org isn't limited to organizations. It works beautifully for anything where you're trying to gather the attentions of people. It works great for forums, it works FANTASTICALLY for geo- I'll even be using a good .org as the main platform for a broader collective of related city guides.
It's OK that some people 'don't get' .org. There are people who 'don't get' New Orleans either, but as the saying goes, if you need it explained to you, you wouldn't get it anyway.