It certainly bothers a lot of neuroscientists. There are so many widely held misunderstandings about the brain that scientists find it extremely unhelpful to have more nonsense spread to millions of movie goers. Other people I've spoken to are more optimistic and think that audiences will realize that the claims are not meant to be taken seriously. I have to admit, I enjoyed Limitless despite the daft premise.
I haven't yet seen Lucy, but it promotes the myth.