So you judge a non-technical article written by a non-technical person on the fact that he doesn't know that two programming language with a very similar name are not the same language?
It shows that the author is not willing to invest a few minutes to fact-check this particular assertion that they're putting in the article. After something like this, one cannot stop wondering how many more assertions in this article are false.
But you should be assuming that all articles you read are full of errors.
You spotted this error because you know the difference between Java and Javascript. But what about the stuff that you don't know? How do you spot those errors?