What you get if you let libs run amok is a "1984" society. Libs who read the book probably wonder what's wrong with that kind of society. Everybody lives in tiny, city apartments, and no one has more than anybody else. Everything is controlled by a central, all-powerful government. Perfect lib scenario.
It's a 'perfect lib scenario' because it was written by an ex-lib -- George Orwell.
After enlisting on the Republican side of the Spanish Civil War -- and learning that the inevitable end product of socialism was totalitarianism -- Orwell became a convert to the blessings of liberty.
1984 and Animal Farm are specifically about what happens to societies run by leftists.
And, you're right, upon reading these books, many leftists will wonder "What, exactly, is the problem?"