If the software's business model was to be free, but be supported financially by ads or commercials, then that is still another business model to give contribution to the authors. It actually does something.

As a user of free and commercial software, I would prefer in my dream world if everything was free under a BSD-like license. As a programmer, I realize that I need to feed myself just as the authors of the software I use do. Apple needs to protect their business model, one of which is that their OS should only run on hardware they sell. It ensures that their employees and shareholders can feed themselves and their families.

Compare that to Xchat, which is free in all forms except a Windows Binary. Reason being it takes significant effort and time to build and test on that platform. Remind has every opportunity to do something similar, by providing binaries and source free of charge for any other platform, but to distribute protection that makes sure that it does not run on OS X without payment or some other contribution. Just asking, without legally binding the end user, to not run it on the platform accomplishes and protects absolutely nothing.