Is exclusively using ‘he’ a style choice or lazy writing?

This week, I was asked to fact check and update one of my company’s older publications. The content had been written by a freelance writer who was now retired. The information in the piece was still valid, so it didn’t appear that there was much for me to do. Then I read this sentence in the introduction:

The author recognizes there are as many female doctors and patients as there are males. The use of ‘he’ includes both masculine and feminine genders. It is not meant to offend the reader but rather to avoid a cumbersome writing style.

Hmmmm.