Well, analyzing the question, it seems to be a little ambiguous: The other answers' side of view is that you are lazy, but there's another point of view, in which you're passive.
Let me explain better, this is what people got from your question (example):
I prefer not to work; I want to do nothing but sit there and relax.
Many words could fit: loaf, laziness, lethargy (though more commonly used with pathological meaning)...
But the other point is:
He's being hurt, but I intend to do nothing.
In this case, passive or liable could fit well.
And even another point (as you said in parentheses):
I believe this can be done in a way far much easier, and as I intend to do as little work as possible, I'll do it the easier way.
In this case, the best terms would be practical or non-perfectionist.
Watch out for to procrastinate; it isn't the same as do nothing.