Pollock is an odd target here in a way, because the man was actually skilled, he produced things which proved hard to copy. Unlike a lot of later very-abstract artists, who really were all about their timing / positioning / contacts etc.
I would have to google a lot but there was a nice mathematical investigation of this, in which the summary was something like that he produced a very consistent scaling of details from very small to quite large, in a way which matches natural scenes. Whereas fake Pollocks don't show this, and perhaps that is why they aren't as pleasing.
Also seems like if you're going to rate a painting purely on how much of a rush it gives you to see it, having a subject matter like war that kicks right at the base of your humanity and then comparing it to an abstraction is a bit of a rigged game... I mean even I could probably write a country song dealing with really simple subject matter that would make my mom cry, it's how people are built to react to stuff like that. But it doesn't mean I'm a great artist.
I would have to google a lot but there was a nice mathematical investigation of this, in which the summary was something like that he produced a very consistent scaling of details from very small to quite large, in a way which matches natural scenes. Whereas fake Pollocks don't show this, and perhaps that is why they aren't as pleasing.