The reason is that they aren't programming related.
These are prime candidates for migration: if they're off-topic on SO now, then moving them here gives them a chance to get answered rather than closed, and helps to promote this site as a resource to users who might be unaware of it.
That said, if you're gonna go through questions on SO and start flagging for moderator attention, it's a good idea to heed kiamlaluno's suggestionheed kiamlaluno's suggestion and stick to questions where the OP has been recently-active. Otherwise, you're liable to end up migrating a dead question that won't bring its author along with it.
After the beta, you can afford to be a bit more liberal with this: the definition for the site will be better defined, and there's less risk of inadvertently offending users who feel their questions are on-topic for SO.
Of course, posting a comment suggesting the author of a question on SO might find this site useful for future questions is fine, even if you can't get a moderator to migrate it.