Check out this link on the book and its teaching guide. From the link:
The Central Park Zoo is home to all kinds of animal families. But Tango the penguin's family is a bit different -- she has two fathers. This heartwarming story will open the minds of readers, resonating long after the story has finished.
"A little miracle for children. Funny, tender, and true, the story of Tango will delight young readers and open their minds." -- John Lithgow
2. "Family" is a prominent theme in And Tango Makes Three. Discuss the concept of a "family." What constitutes a family? Tango's family is different, but how is it the same as any other family in the zoo? In the world?
Looks to me like learning about penguins is indeed a side issue.
Guilty - of anthropomorphization
>>Maybe I'm missing something here
Check out this link on the book and its teaching guide. From the link:<<
From that excerpt it sure does sound like the teaching guide has an agenda. Changing the teaching guide is a different issue than rstricting or banning a book from a school library.
For example, I went to a very conservative private high school. We read the Communist manifesto so that we could understand America's opposition and see the weaknesses in Marx's arguments. A different way of teaching that book could have been innappropriate.
No. 2 gives you the real story behind this book. We're to accept ALL kinds of families, not just a mommy and a daddy. Hmm, sound familiar?