Eben Moglen, in an interview:
The primary desire that businesses have is for control over their own destinies, for avoidance of autonomy bottlenecks which put the fate of their business into the hands of someone else. The difficulty that they experience — that they call vendor lock-in, or noninteroperability — is a difficulty which is really a businessman's equivalent of Stallman's frustration at unfreedom. They are essentially the same recognition: In a world of complex, interdependent technology, if I don't control my technology, it will control me. Stallman's understanding of that proposition and Goldman Sachs' understanding [for example] needn't be as far apart as one might think. The desire to maintain autonomy — the desire to avoid control of destiny by outside parties — is as fierce in both cases as it can get.
Indeed, I still find it difficult to argue that unfree software is immoral (except using very theoretical arguments), but it is certainly bad business sense. Using proprietary software is like handing the reins of your company's infrastructure to an outsider.
What is interesting about free software is that it is a commons which does not suffer from the tragedy of the commons. It is valuable because of its freedom, not despite its freedom.