I've run into plenty of folks who simply did not want to see things in a more rational, logical way. Some folks would rather cling to their inconsistent and fantastic beliefs than to question them and consider new possibilities.
Something else to consider, is the power of "might makes right." There's a certain amount of truth to the argument that being the loudest or more dominant one in a debate carries some level of comfort, and where there is such comfort in the acceptance of an ideology or falsehood, there will be followers who will gladly overlook any errors in their thought in exchange for that comfort and support. Not everyone strives to be correct and consistent - some strive more to be "mainstream", "alike", or to just fit in.
With some such folks, revealing "truth" or debunking falsehoods will only get you dismissed or ignored. o.O