This is a logical error.

Over 55s own about 73%

What this number establishes is that a significant portion of the owning class is over 55. What it doesn’t show is that the boomers are the ownership class. If one guy over 55 owns 75% of the country, you still end up with

Over 55s own about 73%

being true. You’re focussing on the wrong group of people.

Here's a fact:

Households with a white householder hold roughly 80% of the nation's total wealth

Does this mean we should be mad at white people?