Why save them?

[Inziladun]

Originally Posted by Lotrelf

Wasn't he a Messenger of Manw�0Š5? This Eagle theory is too simple and may I say silly?

The Eagles in general were servants of Manwë. Therefore, as lmp said, they would not have accepted such a task. The point of the Istari was to give the Valar an indirect means of aiding Middle-earth against Sauron, not to do the job for them.