How real should nonfiction be?

How closely should non-fiction authors adhere to the truth? Can they make up things in order to convey facts? How far should authors of nonfiction go in entertaining children as they seek to inform them? Located on nonfiction lists you can find:

1. A book about a meteor told in the first person by the rock. (Call Me Ahnighito by Pam Conrad)
2. A book based on the words of an advertising writer that purports to be a speech by a famous Native American. (Brother Eagle Sister Sky by Susan Jeffers)
3. A book about penguins in Antarctica that describes them as having friends and panicking at the approach of helicopters. (Helen Coucher's Antarctica)
4. A book about architecture that tells children that buildings that tells children they can
5. talk to buildings. (Forest Wilson's What it Feels Like to Be a Building.)

At the same time there are works of fiction such as the "Dear America" series from Scholastic that seem to try hard to look like nonfiction materials. Are authors and publishers obligated to help children become critical readers or to produce best selling books? What do you have to say about these ideas?