In a recent article for LPI's blog, Jon "maddog" Hall in true festive 
fashion outlines "Ten Reasons Why You Can't Use GNU/Linux" ;-) 

"Many years ago I was still working for Digital Equipment Corporation, but I was also going around the world 
talking about Free Software and GNU/Linux.

As I talked with people, they would come up to me and say “I would use Linux except it....” and they would go on 
and give their reason why they were not using Free Software. I would 
then tell them why their reason either had never been correct (it was 
FUD from some closed-source company) or it was no longer correct (it had
 been correct at one time but was no longer an issue). After a while I 
realized that for the most part I was answering the same questions over 
and over again, so I wrote a talk called:
“The Ten Reasons Why You Think You Can't Use (GNU)/Linux”

subtitled:
“And the Ten Reasons Why Those Ten Reasons Are Crap”

Please read more:
See: http://www.lpi.org/blog/ten-reasons-why-you-cant-use-gnulinux