Seattle people are nice but also distant

The Seattle Times had a great article about the big problem in Seattle that does not get talked about; why people can be so nice but at the same time so antisocial.  Julia Sommerfeld did a good job in her story “Beyond Social Dis-ease: beyond the smiles, the Seattle Freeze is on.” It really was in interesting read.
The big company I work for hires people yearly worldwide and it is amazing that they receive such a cold shoulder when they come to work.  I have personally witness time and time again a person looking for something do hinting for the invite that never comes.  Luckily the new hires seem to band together and you see some rich friendships develop.  Many times you see people hired the same summer go on to be the best man or maid of honor in another co-workers weddings years later.  I do not know how many times I have had an extra ticket to a play or game and when you send out broad solicitations to see if someone wants to go it is rare to get a reply.  People just get locked into doing what they do and hanging out with those that they really hang out with and do not go outside of that circle.  I have said this many times that living in Seattle it always feels like you have few close friends but many acquaintances.
When I tried to think of why people in Seattle are this way a few things came to mind.  The first was that Seattle is fairly spread out.  As they point out in the article many people have houses so there is not that community that builds up in having areas where there are many apartments or condos create a little city within a city that you see in other big cities.  When I think of a city like Chicago there seems to be a bar, family owned store, and maybe a laundry on a corner every few blocks and I think that tends to build up more of a community.  I think that the lack of public transportation also keeps the social interaction down.  You do not see the same people every day riding the bus or train unless you are the subset of people that do.  I also think Seattle is a bit weird in that people really seem to like to do stuff on their own.  People will go off hiking or camping more than other areas and you do not meet a lot of new people out in the mountains.  

I am curious what others think.  I personally try to include the new people I meet at work but over the years the age thing makes it hard to become close friends.  Outside of work I really seem not to be in situations where I can meet new people (being at home seems to be the key reason ).  Anyone else have answers on why Seattle is the way it is?