... all seem to use the same slightly weird anachronistic phraseology ...
To be fair, that's not exclusive to Miscellany. I receive a lot of magazines from clubs and organisations and the contributions are almost always in that same semi-formal style. Contributors rarely write as they speak but rather prepare their submissions as if they are writing to the local council to complain about the bins.
One very common example is the word
purchased. Open any club magazine and I guarantee you'll find somewhere a phrase such as "I recently purchased on a well-known auction site..." as if the word "buy" is too informal for publication. "I just bought on eBay..." is much more readable.
