I've never really been a fan, but I don't think of him as a shit writer. To me, he's always been a writer who had interesting ideas but the execution was a wee bit pedestrian. I think he's always been best doing graphic novels with an artist who can really make those ideas pop.
There's an interesting question there about more literary male writers and how they handle female characters. I love me some John Le Carre, but I have to admit that in a very long career he created three, maybe four, rounded female characters, at least two of whom were based on people he knew. Most of his female characters tend to fit into easy categories like victim, totty or shrewish wife (the last much in evidence when his first marriage was collapsing).
I'll cut him slack for being a man born in the 1930s writing about a very male world, but even he admitted he struggled with female characters. And from the way he wrote women, I wasn't at all surprised to find out he was a serial adulterer.
I think it's a definite blind spot for male literary authors. I can think of plenty of pulpy genre authors who might seem more sexist on the surface but have little trouble creating smart and capable female characters.