like any writer/novelist, George Orwell has his weak and strength points. Could you please help me to figure out why Orwell, despite his expert masterpieces and themes, is disliked by many critics?????

I have not read a lot of criticism of 1984 because, as you mentioned, this is a masterpiece. I would be inclined to think that any criticism of this book might come from the critic's own political viewpoints rather than the book itself.