It's a common objection.
'This modern style of writing is all very well, but...
I work in enforcement/my stuff might go to court/I want to show I'm being professional.'
Time for some plain English. I'm going to be less diplomatic than I would be in a workshop.
Let's get controversial.
Formal business letters are not more professional. They're just odd. They're not better service; they're aloof and cold and say, 'This is our routine letter because we couldn't be bothered writing one especially for you'. Any manager who insists on formal language for business letters and reports is wrong.