If you read the article, you'd know that capital gains are included (since cap gains are included on federal income tax returns).

The poor pay a disproportionate amount in regressive taxes such as sales tax. One must look at overall burdens and overall ability to pay.

Yes, the poor consume disproportionately, and pay a disproportionate amount of consumption taxes. All that says is the rich consume far less than they could, and are much less of a drain on society than the poor.