I think this activity helps to practice and develop the English grammar and writing skills, I consider it a good method to learn because it is not monotonous or boring, instead it makes us learn in a enjoyable way, but i think that it would be a good idea that each person could decide the topic that he want to write about , not to have a topic chosen by the group or designated by the program, because it might be easier to express your feelings or what you really want to write.
Personally I would have liked to write more about simple topics as my favourite food because in this way It would better and more close to what you want to share in your blog about yourself.