How does this aid scholarship?
Any historical dating system needs a year zero. Inevitably, this is in a sense arbitrary, although it makes sense to tie it to a universally understood event.
When looking at things that happened millions of years ago, we say "BP" which is "Before the Present". The present is advancing very slowly compared to a timescale of millions of years. 3–5 million years BP will still mean pretty much the same in 500 years' time.
However, BP doesn't work for recent history; you would have to update the history books every year or two. Instead you need a datum, and that means some dates will be before and some are after the datum.
When setting up any system or standard, it is wise to look at what is already in established use. There are thousands of history books extant with dates linked to before or after the nominal estimated date of the birth of Jesus. Ask any Englishman the date of the battle of Hastings, or any American the date of the declaration if independence, and they will give the same number. Changing all those numbers to relate to a new datum would serve no useful purpose, and cause confusion.
However, that does not mean that it is good for scholarship to assume that the whole world accepts the Christian world view. 69% of people in the world reject it or at least do not accept it.
AD is from Latin ( a dead western European language) and refers to Jesus as "Lord", which most of us do not believe to be the case. In some countries, openly referring to Jesus as Lord, or the son of God, might be blasphemous, and in others it may simply not be understood.
The sensible compromise is to keep the numbers, but to use a designation (BC/BCE) that does not carry any cultural baggage or make any assumptions. Regardless of their cultural backgrounds or religious beliefs, scholars can agree to use a common numbering system, and to use the existing datum, but that does not mean that they must feel comfortable with "Before Christ" (we are still in the time before Christ to a Jew) or Anno Domini (no Muslim —1/4 of the world's population — or Hindu, or Sikh or Buddhist, or atheist, would call Jesus "Lord").
So BC/BCE is imperfect, but a sensible compromise: a simple change rather than a major one. That is why it has gradually become more common
over the last 400 years.
A problem with any historical scholarship is the covert assumption that one's own culture is somehow the norm and that everyone else's is assessed by how it relates to ours. In my own case, I went through school and learned in detail about the battles of Crecy, Poiters and Agincourt (English victories) but was never told that we lost the 100 years war. I learned nothing about Chinese history, and the only things I learned about American history related to when "we" discovered America, and when eventually we lost the colony.
Any change that takes students away from this assumption that our own local cultural worldview is the starting point for understanding world history must surely be helpful for scholarship.