Michelle Haimoff has been presenting a series of daily posts on She Writes regarding her five reasons not to get an MFA. Although I am a graduate of an MFA program (University of Florida) I think there are plenty of valid reasons not to get an MFA. That said, I think it's important to make sure the reasons that you think you shouldn't get an MFA are rational.
Reason #1: Privacy
Haimoff states"the problem with enrolling in an MFA program is that it’s a public statement about how you’re spending your time. It invites questions like: “What are you working on?” “What is it about?” and “How far along are you?” Grad school is basically your job and, if you’ve ever been in the outside world, you know that you are always expected to be able to talk about your job."
I think it's important to make a distinction between being to expected to "talk about your job" within the program and without. Other writers share the fears that Haimoff mentions. The vast majority of your MFA peers are not going to be asking you to describe what you're working on. Of course, you'll have to share your writing in workshop, but the prevalent model in which the writer is silent takes care of the problem of talking about your work in that context.
Being afraid of being on the receiving end of probing questions at the holiday dinner table is never a good reason not to do something. There's a simple, graceful way to respond to the questions Haimoff mentioned:. Tell the curious party that you prefer not to talk about your work in progress. Sharing some of the concerns Haimoff lists, such as "you may not know exactly what your story is about yet or how far along in the process you are" can be a good strategy. However you phrase or explain your refusal will depend on who's asking. You can be curt, bashful, gracious--whatever the situation requires. Being enrolled in an MFA program does not mean you get a sodium pentothal injection at orientation that forces you to talk about your writing.
If you are still coming to terms with identifying yourself as a writer to the outside world (and let's face it, it's a process with lots of challenges), declaring yourself a writer by enrolling in an MFA program is not the greatest vulnerability you should worry about. A writer shares his or her work with the world, often by attempting to get it published in various outlets. Sending your writing out for consideration by the editors of the world requires acknowledging to yourself that you are a writer. This private statement is far more important than any public statement could ever be.