I belong to a large guild and yes, there are a few people that make perfect quilts and will critizice others, but those are the minority. The majority in my group make good quilts and share their knowledge and experience by holding classes and workshops, and then there is a very large group that make not so good quilts, and are there to learn. As you grow in the guild you will move (not Knowing) from group to group and will have a lot of fun. My favorite part is show and tell, even though I am jealous because I see a lot of women (no men in my guild) that spend most of their day sewing, while I hold a full time job and daydream about quilting. The next day after a meeting I want to call in sick.
I find that even the quilts that are not so perfect will get ohhs and ahhs during show and tell, because most of the time the imperfections are only noticeable to you. A quilt with the right color combination and best of all, with a great story behind, doesn't need to be perfect. From the distance of a chair in a school cafeteria, for example, you don't see corners that don't match or cut off points. You just see a woman that spent time making a quilt and is proud of it, and just the fact that she stood there is a wonderful thing.
I say join the guild and enjoy. Take all the classes that you can. You will not regret it. The good thing is that if you don't like it, you can always leave.
Maria