As Canadian Poet Patrick Lane once remarked, writing is the easiest thing in the world not to do. Despite opinion to the contrary, Creative Writing Classes do produce literary writers whose work measures up at the highest levels in the literary world. But most, if not all of these writers don't begin to produce publishable, i.e., their early best work, until they reach the Masters level, until they've done years of creative writing workshop work and study. The production of great, or even publishable, work is not the measure of a creative writing class's success. But the fact that creative writing students don't begin to cultivate the individual and social systems that encourage them to reach this level of excellence until they've completed years of study is significant.
Students leaving undergraduate creative writing classes are at a disadvantage.
They've seen what they can do, or they've seen what they might do, but for the most part not how, and how hard it is, to do the same outside the class. What they lack is a communicative tool. We don't challenge that assumption, and encourage our students to form such groups. But few do. There are some purely online writers groups, and they are popular.