Why not? If nine or so reasons pop to mind, try this: 

• Objections to Speaking Latin & Justin Slocum Bailey's responses thereto.

And also, read these:

• The Persistent Perks of Speaking Latin by Justin Slocum Bailey
• Why Oral Latin? by Susan Thornton Rasmussen
• Why Speak Latin? by Nancy Llewellyn
• Did the Romans Really Understand Cicero? Live, in real time? by John Kuhner
• Summer fun is speaking Latin! by me, Ellie Arnold