In the year AD 525, a monk named Dionysius Exiguus calculated a set of tables laying out several of the future dates of Easter. The dates on previous such tables were notated in the customary manner, anno Diocletiani, or "in the year of Diocletian," counting forward from the first date of that Roman Emperor's reign.
Though many Christians had begun to use anno martyrum, or "in the year of the martyrs," as a result of Diocletian having ordered the last major Christian persecution, Dionysius thought it less than desirable to reckon years on a Christian calendar in reference to such a man. As such, he invented a new system, anno Domini, or "in the year of the Lord," counting forward from the date of Christ's Incarnation and providing an explicit conversion from Years of Diocletian to Years of Our Lord.
The practice became widespread in Europe when, in 731, the Venerable Bede used it in his Ecclesiastical History of the English People, gradually gaining more and more traction over the succeeding centuries. We now know that Dionysius' calculations were somewhat mistaken and Christ was most likely born a year or two before 1 BC. Nevertheless, the Gregorian calendar, using such a system, has proved so accurate and become so standard, that no one dare change it.
Until now. The BBC is the latest in a string of respected institutions and publishers to reject AD and BC in favor of the "religiously neutral" CE and BCE ("Common Era" and "Before the Common Era").
But wait, because the reckoning of years from the traditional date of Christ's birth is so universal, it would be all but impossible to attempt to force an actual change in the system of dating. Instead, to try and avoid an explicit reference to Christ, they just changed the terminology. The thing is, though, they're still counting from Jesus' birth; they're just trying to pretend they aren't.
My thinking is, if you're really going to try to entirely excise religion from the public sphere, you should do it right. Devise a completely new dating system and impose it on everyone carte blanche. Maybe they'll react the way the French did when the revolutionaries tried the same thing, maybe they won't. Don't know if you don't try.
Is it really so offensive, though? Yes, it refers to Christ, but it's not like putting AD or BC before a date means you think he's God like we do or came back from the dead. They're not even religious terms anymore. They've been so utterly and completely absorbed into Western culture that the majority of people don't even know what they stand for.
Just relax. You won the battle for academia, and you're winning the battle for the West. You don't have to rub it in.