While banning Safari is very strange, the author acknowledges the browser issue:
"I know many would fault me for [not supporting IE] on TNL.net but the design decision of not supporting older internet explorer browsers was based on analytics data that showed me that only 5% of my overall audience was using those"
Remember, ignoring IE users is not necessarily about elitism, but can also be a financially sound decision.
It can also kill his future growth if he doesn't keep whitelisting each end every new browser signature (for find a better way to lock out old browser users).
It's also not a good idea to be condescending to your users. The tone of that message is anything but friendly. The "banned" message mentioned in another comment even less so.
"I know many would fault me for [not supporting IE] on TNL.net but the design decision of not supporting older internet explorer browsers was based on analytics data that showed me that only 5% of my overall audience was using those"
Remember, ignoring IE users is not necessarily about elitism, but can also be a financially sound decision.