BCE: Before Common Era
And what is the Common Era? Oh yea, the time beginning with Christ. No matter who you are or what you believe, Jesus actually existed and his teaching radically changed the history of the World. So much so that the timeline based on His life became the common calender. So why pretend differently?
No one would be doing this if the calender were based on the life of Alexander the Great. Its just another example of Christphobia in academia.