Writers is still in beta. Migration paths are usually only added to graduated sites. For example, there was no migration path from StackOverflow to Programmers until the latter went out of beta, even though many, many people wanted to have one right away. See e.g. here and check the top answer by Shog9:
[A site being in beta] means two thing[s]:
It may well be killed off. In which case, questions migrated there would be lost. Not that that's necessarily a bad thing...
It isn't fully defined yet. So it wouldn't necessarily be clear which questions were appropriate for migration.
said quoted, I would support migrating certain questions to Writers manually. (Easy to say, I know, as I wouldn't be the one in charge of actually doing it.) I have commented to that extent just two days ago, after Jeff Atwood mentioned that "quite frankly, [Writers] desperately needs our help to survive". Looking at the Area 51 stats, I can see what he's talking about, and I am all for helping them out. In fact, they are struggling with the same metrics we used to struggle with (number of questions and visits per day), so I totally feel their pain.
On a more general note, see this related question by Eldros: On Migrating and Dispatching: redirecting off-topic question from and to EL&U.
Update April 15th 2011: a migration path to Writers has been added.
Please put it to good use. By which I mean,
- don't just vote to close, but vote to migrate questions that would be a good fit for Writers and
- don't just vote to migrate, but vote to close obvious rubbish that doesn't belong anywhere.