From what I've seen from my friends etc, they all use Launchy (if even that) because that is the first launcher app they came accross and are just used to it. FARR is somewhat difficult to find, I guess because of the name. And if you find it somehow it requires some setup to bend it to your needs, and most people don't want to "waste" time. I like FARR just because with minimum effort you can do just about anything you can think of, and that makes it a great tool for helping with everyday tasks.
People also complain that non-indexed search is slow, but do not realize that if properly configured, FARR doesn't need to search more than a couple of hundred files and folders, and that is really not a big deal on todays computers and is done in a matter of milliseconds. If you really want to instantly search your entire disk use Everything, Locate32 or simillar app. FARR is not made for that.