Talk about missing the point that Gary Stevenson was making. The point he was making was not that the tax policy of the 50s,60s, and 70s meant the rich paid a bigger share of the income tax in aggregate, or that the income tax brought in was a higher percentage of the GDP. The point Gary was making was that inequality (wealth and income, but especially wealth) was much lower back then and has been growing ever since.

The data in the article proves Gary's point. Not only is income tax brought in less now, but more taxes are VAT (sales taxes) which are regressive. In other words, the poorer people in society are taking on a bigger share of taxes. They are transferring them from a progressive tax system (income and wealth taxes) to a regressive one (sales taxes and VAT).

Talk about missing the whole point of Gary Stevenson's argument. The point was that inequality was less back then and the tax system was one reason why. Now inequality is high and keeps getting higher. So yes, we want to go back to the tax system of the 50s, 60s, and 70s not because of getting extra taxes, but because it slows down and may reverse the rise in inequality.