It's not necessarily a principle of socialism, its also a principle of capitalism, and a conservative movement in legal theory.
It's called Pareto efficiency. The use of eminent domain makes everyone better off overall without making anyone worse off (the definition of Pareto efficiency). The person whose property is seized is justly compensated, so he doesn't lose or gain anything, while everyone else now gets a project that will help the economy.
All this takes away is the right of property owners to extort unreasonable compensation for their property as a result of the power they get from holding out. This is a transaction cost and is an inefficient deadweight loss whether you are a conservative or a liberal.
Now, there are two ways in which the transaction may not be Pareto efficient: (a) if the new project does not actually increase overall public wealth, and (b) if the original owner is not fully compensated so that he is no worse off than before. The first is a political question that need to be evaluated by elected officials before making the seizure, but is really not the province of the courts. The second is fair game for a law suit, but one that attacks the seizure on the "just compensation" clause and not the the definition of "public use".
As Emsworth said, Pareto efficiency is irrelevant. This is a thread about the validity of a court ruling, not about policy making. Economic development is not a public use as understood by the authors of the Fifth Amendment.
As far as policy making goes, you are focusing only on financial gain or loss. There is no dollar figure you can put on your rights. When you take away the Constitutional Rights of an individual you've taken something away that's worth more than whatever these people were given for their compensation.
Now you care about what the authors thought?
To bad you can't keep that line of thinking regarding the "welfare clause", or the "interestate commerce" clause.
