Ending for animal farm: good or bad?

I feel that the ending of the story "Animal farm" is not a very good one as the ending writes that the pigs were in good terms with the humans ,which was not what Old Major had predicted at the beginning of the story. In the end, the pigs of Animal Farm were corrupt, and did not help much in the development of the farm. Instead, they were better fed than the other animals and were able to make the other animals do the work in the farm. They adopted human vices, such as drinking alcohol, and did not follow the seven commandments of Animalism. However, as the other animals in Animal Farm were simple-minded, they were pitiful as they worked very hard but received little food. Animals such as Boxer and Snowball , who contributed much to the farm, were killed instead, which was sad as the ending would have been different. ( the animals would probably be enjoying their life in the farm)