Why not make full use of the eagles in The Hobbit?

In the books the Eagles are:

sentient and capable of speech

In the movies (The Hobbit, Lord of the Rings) we never hear them talk.

In the book The Hobbit Gandalf doesn't call for the Eagles to help, but:

Luckily for the company, the Lord of the Eagles has seen the commotion from his roost high in the mountains. With a number of other eagles, he swoops down, picks up the marooned travelers, and flies them to safety.

The eagles are friends of Gandalf’s and enemies of the goblins. They are happy to provide food and rest for the weary travelers, who then continue on their journey.

and

Although the eagles help the company tremendously, they express that hatred for goblins, rather than love for dwarves, is their main reason for helping the company.

... the eagles [don't] have any interest in the dwarves’ gold, but as representatives of pure nature, they are the sworn enemies of corrupted nature, represented by the goblins and Wargs.

The eagles generally keep distant from the affairs of other races...

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There has been a similar question regarding the Lord of the Rings:

There are a couple of theories about why the Eagles weren't used.