Nope, it isn't. Composers get it too, as do artists. There's a difference between tactile work (carpentry, accounting) and creative work.
According to the director of Penn State's Master of Fine Arts program, writer's block is most often rooted in performance anxiety.
Unless you're writing fiction and don't know where the story goes. That happened to Franz Kafka. A lot. He died with more unfinished novels than finished ones.
And, for what it's worth, there's no such thing as laziness. That's from a professor of psychology. Which means not just trained in psychology, but enough to teach it.
Just because some people don't experience a thing doesn't mean no one does.