Guilds are like any other group.. There are great people all over, you just have to be patient enough to make new friends. I think quilters are generally open to new people, love others to join.. but some of the people who are already there may be a bit on the shy side to and don't make friends that easily either.. I say, go, have fun, keep introducing yourself.. share something, volunteer, and pretty soon you'll find yourself a part of something wonderful.
On the other side, like all groups, you may just happen to run into a group with a problem leader that is making everyone miserable. Or just isn't your cup of tea. Or is too social/political/demanding/uninvolved/not actually quilting any more, lots of things. That's okay too.. try another guild!! We all need each other and the encouragement of friends. Don't allow one experience to color your feelings about guilds in general. They are all made up of people so there is bound to be one you'll love, and some that aren't for you.