I imagine their reasoning is similar to The Economist's for having anonymous bylines:

"The main reason for anonymity, however, is a belief that what is written is more important than who writes it. In the words of Geoffrey Crowther, our editor from 1938 to 1956, anonymity keeps the editor 'not the master but the servant of something far greater than himself…it gives to the paper an astonishing momentum of thought and principle.'"

https://www.economist.com/blogs/economist-explains/2013/09/e...