I think this is true and would add it is also true of the alternatives people suggest like forming your own writing group, working at a lit mag, freelance writing, going to Clarion, etc.. Although these days its so tough networking might not help as much as it used to… (Note I’m just talking about the careerist aspects here. I think there are lots of benefits to having dedicated time and space to practice your art with likeminded peers, whether in an MFA program or outside of it.)