What the Fallacy?!
Appeal to Tradition
The Fallacy
Arguing that something is right or good because it is traditional or has always been done that way.
Why it's wrong
Just because people have done something for a long time doesn't mean it's good or right. Slavery was a tradition in many cultures for centuries, but that doesn't justify it.
Example
The board of directors rejected the proposal to use email for communication, arguing that the company had used carrier pigeons for fifty years and it would be disrespectful to change now.