N.orgs definitely have value. In addition to my L.org portfolio, own 8.org and have already declined offers as high as $150k. I doubt anyone would dispute that 8 is probably the highest value single number.
It was worth more than what they paid in 2009. Domainers buy, hold and resell not everyone buys everything register fee. Ever wonder what number a domain will sell for if it doesn't resolve or ever tried making an offer?