Greatness isn't just in terms of difficulty in execution. It's also innovation, grandeur, waves made in the public, etc. He was a leader in his style. Many of his works were quite large and speaking as someone who has painted art it's surprisingly hard to get larger scale to turn out with the right lines and perspectives. And his fame and support in the broader public is solid.

Personally I would still rather have a Rembrandt or Van Gogh or some other impressionist style work. But that doesn't mean Pollock isn't also great.

Pollock was the creator of action painting and earned himself the nickname " Jack the dripper " , he carved out his place in art history as innovater giving rise to the abstract expressionist movement , his way of painting signified the dawn of new era in visual arts .

Personally I'd much presfer a Sisley anytime , my favourite painter of all time

He was innovative in that he did something successfully that not a lot of people had done. I think in that idea it makes him a great artist. Can his work be mimicked? Probably. Do I find his work fantastic? Some of it. But I'm neither an artist nor have I the privilege to say I've studied it.

Yes he was! His earlier work shows his talent of composition, accuracy of human proportions, perspective, etc. His splatter work shows unique and well thought out color schemes. Plus, he is the first to create that type of painting and therefore deserves the credit and money.