CT & NJ are on this list because of NYC. Fairfield County is where many of the ultra-wealthy from NYC live-they skew CT's numbers drastically. I'm sure there are similar parts in northern NJ. For that matter, NY state outside of the NYC region is totally different-think a hilly Iowa with a lot more snow.
Like IrishScott said, centers of economic activity generate money. No real surprise there.
I don't think it is the different between high and low tax states, I've lived in both. What I look for is EFFICIENT spending of tax dollars, with a minimum of waste and graft so the populance gets the most bang for their bucks.