I actually disagree on this point. I don't go along with the snobbier literary types who say this (who look down their noses at genre fiction generally). I think her prose style is very good, and her books are going to be remembered the way Dickens, Austen, and so on are remembered for years to come.
Other than that, this is an excellent article, and I completely agree. I admire JK Rowling enormously, for her courage, tenacity, success, and of course for giving the world some wonderful novels (not just the Harry Potter series, but also the Strike series).
And yes, the death threats against her are absolute lunacy, and do the trans lobby no favours at all.