I was reading this earlier today and agree totally. There are lots of other points I can think of, but this covers it for tons of users, even if you are not a power-user or developer.
The thing is that even with all of the Linux and Open Source activism, so many people out there just don’t seem to understand what the difference is, or that they have choices.
Do someone a favor: Find a full-featured Linux Live-CD Distro (like Slax or Ubuntu), download the image (bit torrents are usually fastest, use Linux Tracker, and leave a copy or two around. be willing to walk someone through some of the basics. My usual walk-through includes Firefox, GIMP, GAIM, AbiWord, and sometimes part of OpenOffice or KOffice, depending on where the discussion goes. The best part is that all of them (except KOffice) are cross-platform, so I always point out the fact that any of them can be downloaded and installed on their Windows box for free as well.