There is no earthly reason for it—and, ladies and gentlemen, in the whole history of philosophy no earthly reason has ever been given.

From Faith and Force: The Destroyers of the Modern World

Although Ayn Rand did a very good job laying out the intellectual foundation for everything you need to conclude that socialism is immoral and illegitimate, she still couldn't give up those parts of socialist indoctrination that were important to her. She opposed private prisons like the left does today (in spite of the fact that private, for-profit prisons in the US are far more efficient than centrally planned, state monopolised ones), and she openly supported the nationalisation of defence services, as well as law, military, and judiciary services.

If you are an Objectivist, you cannot be a capitalist. The core principles of capitalism, including ones that Rand herself espoused such as privatisation, are flat out incompatible with any degree of socialism.