"The authors disagree with the common perceptions that a demotivated employee is lazy"

I was wondering about this the other day - does lazy have a real meaning? I thought through some options and came to the conclusion that it's a nondescription used to close off any further enquiry and also used as an insult.

It doesn't explain anything, it's a proper phlogiston answer.

Not doing something could be lack of motivation (that doesn't matter), lack of interest (I don't want to paraglide), other priorities (I would but can't right now), lack of skill (I want to but can't), fear of various things (if I start I will only draw attention to this, what will people think, what if I fail), but lazy? A nonsense word which I should stop using.