The Free Game Lag
There is one category of software that many see as being unsustainable as free software: Free video games have lagged behind other areas of free software, and the reasons behind this are fairly simple.
Still, even many free software proponents may fail to provide an answer to those who are skeptical about the viability of free gaming. While it is true that software should be ethical, video games need not suffer for it. The business models for production simply need to change, and just like they have for other software, they will for gaming as well. When people ask you how gaming as we know it can exist in a free software world, you should open with your response with, "It can't, but it can be better."
There is a natural tendency for free software to take on more essential aspects of computing first.