I believe that having flighted parrots is a very gray area but I do lean towards flight as the healthier option and my birds are flighted. I think the best way to spread the word is to educate, rather than berate or belittle somebody for their views so... here is an article I found on the merits of keeping your parrots flighted that I thought made some very good points. (it is my sincere hope that this thread does not cause any arguments although thoughtful discussion is encouraged!)
http://theparrotuniversity.com/flight.php