"Lazy" is a word we use to insult someone who doesn't do what we want them to do.
In that sense, it is an expression of frustration at how weak our external influence is on other people. Many parents have called their children lazy, and many teachers have said it of their students. However, in doing so they have underestimated the importance of the child's intrinsic motivation. In fact, laziness is actually a good indicator of a strong internal drive, because it shows the impotence of external influences to overpower it.
In the worst cases, some people have internalised the insult and used it against themselves. However, those situations still involve a failed attempt to overpower the internal, emotional drive.
The conclusion here is not necessarily that the internal drive is always correct (although there are good reasons to believe that it often is) but that it is usually the strongest factor, and we would therefore be most effective when working with, rather than against, it.