Whether you go along with the argument or not is a total irrelevancy.
The abbreviation is prevalent and unlikely to go away. It is vital there is a fixed datum point for dating. The who,what,why,when,where of it's determination is trivial, the essential thing is that it exists and can be understood by all without any potential political/religious baggage attached.
To make it "before present" would become meaningless rapidly.
Perhaps you would like each religion to have their own unique dating system to be used. That will work well in the digital and satellite age. It would be like trying to construct railway timetables when every town and village kept it's own unique time.(the railways brought about standard time in the uk, the alternative was chaos)