That's not an especially compelling argument. The Top 10% hold more than 77% of the wealth in the United States [1, 2]. And are much more efficient at converting short-term income into long term wealth than the lower 90% [2].
[1] http://www.levyinstitute.org/pubs/wp_589.pdf [2] http://gabriel-zucman.eu/files/SaezZucman2014Slides.pdf