Are these the fifty you would have chosen?

[Imladris]

HP and LotR are completely different, and while the creator of the list says she made fantasy "cool" again, Tolkien didn't create Middle-earth so people would think it was "cool."

Neither did J.K Rowling. Inspiration came to her and struck, just like it did with Tolkien. It is the compiler of the list's opinion that she made fantasy cool again:

But I personally feel she is majorly responsible for making fantasy "cool" again

The only reason that J.K Rowling should be on the list is if she made Tolkien's works more popular. In other words, if she did make fantasy popular again, thus making Tolkien popular again, then she should be on it.