I do not agree with the previous answer. I would argue that Marxists would see The Prince as a valuable guidebook for a ruler. It is true that they would argue that class struggle is important, but Machiavelli's work could easily be seen as good advice for the ruler in a Marxist society.
Marxism argues that a society typically needs to have a vanguard party that will impose a dictatorship of the proletariat. The leader of such a party would surely need to act in ways similar to those that Machiavelli advocates. The leader would need to use all possible means to maintain control over the country as he moves it towards true communism.
Machiavelli's is a practical guide for the ruler, not a prescription for what the social and class structure of a society should look like. Marxists would be drawn to the practical advice for keeping control over a population.