How important is it for writers to get together? I feel that the fellowship and the knowledge one gains from communing with like minded individuals is valuable.
Conferences can stir the creative juices and stimulate the mind. Not to mention the networking possibilities. You not only get to rub elbows with leaders in the industry (publishers, agents), but you get to meet other writers, some published and some not. Oh and what you can learn from these new contacts is invaluable.
Writing groups can also stir your senses. Sometimes exercises are introduced that may help you in an area you are having trouble with. Also, speakers offer invaluable insights into the publishing world and different types of writings. Plus you can read your work. It is important to read your work out loud, so you can see if the flow is good. Also, feedback from others will make your work better. Not all criticism is created equal... It is important to remember that you are trying to help the writer, not destroy them. Also, not every writer receives critique the same. When you get to know someone- you will discover who only wants to hear their work was great and those who really want to make their work better. If a group isn't working for you, why not figure out why and maybe start your own group.
Often writers will get together on their own in small groups. Writing is discussed, critiques are done and even sometimes writing is done during these informal meet-ups. Plus it is a great way to toss around ideas with people you want to be with.
Open Mic's and Public Readings are instrumental in getting your name and work out their. These also get you comfortable sharing your work with the world no matter how tiny the venue.
All in all I think that writers often seek each other out for encouragement.