Well, most of the time they even don't know about it - so then, it can be one way to inform people about these alternatives, no ?
I participate in a local association to help with the installation of Linux for beginners ; i can tell that when you take time to inform about these free software and their ethical and positive aspects, people will try to use them as long as they can adapt.
People who like to try to install Linux maybe also wants to do what they are use to do with their computers or even knowing it's possible within the software in Zorin and maybe they also want to get rid of proprietary software.
If so, the question is about how to inform and make people want to give a try, a credible entry into free software. Zorin (and others) can play this role i guess.
But as Aravisian said :