Academia is a much easier, low productivity, self-interested career than engineering in my experience. Most academics claim they work hard but have very poor time management and work intensely in short periods whilst taking huge amounts of holiday and flexible time off. Most universities are empty during the summer months. Even at top tier universities in the UK I was shocked how absent people were around anything remotely close to a holiday period.

In the commercial world you have to sing for your supper, as PG put it, and that is much much harder.