To get it out of the way, Orwell was a communist/socialist (at least when he wrote this).
To deal with the book from an educational perspective: I loved the book and it's an important book in our literary heritage. I also did it for my lit exam and my lessons were most definitely not about slating communism at all and our teacher didn't treat the book as 'righteous'. The purpose of studying this book is that there is a lot of stuff to write about e.g. allegory, the different themes, context etc. It's a great book for teaching students analysis.
To deal with the book from a more political perspective: most people think this book (along with 1984) is a critique of communism when it isn't. It's a critique of the USSR and it's totalitarian, genocidal dictator Josef Stalin (Napoleon in the novella). Orwell was unusual at the time of its writing as he was one of the few English communists/socialist who criticised the USSR and his book was an outlet for those criticisms. If you read the book, communism (animalism in the book) isn't portrayed negatively. If anything, it is the saviour of all the animals on the farm from their cruel master. Napoleon, however, exploits the animals so he can live a life of luxury. So the book is about greed more than anything, with some ignorance and naivety thrown in.