Does it matter what the super-rich are doing with their money? Are those who complain about the extravagance not just giving expression to their envy?

I cannot deny it: I wish that I had millions to spend on what I liked, i.e. helping to create a fair, humane and sustainable society.

As to whether or not it matters what the super-rich (or just the plain rich for that matter) do with their money: it matters to the extent that human survival depends on it - that is how much it matters.

It is not just that the rich and super-rich are placing a far greater drain and strain on our planet's finite resources and carrying capacity than anyone else, but even more importantly, that through the media they act as models of "success" for millions (ultimately billions) of others, who adopt the same values and strive to emulate, as best they can, their extravagantly materialistic lifestyles. 

Even the average Briton's lifestyle is extravagantly materialistic and non-sustainable (when multiplied by 6-7 billion), and we should ALL be deeply ashamed of what we are doing to our planet, plundering and spoiling it for future generations (our own children and grandchildren). But instead, most people take pride in showing off their share of the booty: the more loot they acquire, the greater their "success" and pride.

It is interesting that the report actually makes fun of how the some of the world richest men are competing with each other to have the biggest yacht: grown men behaving like children. And it would be funny if only the consequences were not so tragic.

The reason is that as individuals and as a society we are still very much dominated by our "more animal than human " nature. Our economy is based and dependent on it.

The immortal words of James Lovell, the commander of Apollo 13 when that spacecraft's lifesupport systems were damaged by an explosion en route for the Moon apply equally well to Spaceship Earth: "Houston, we have a problem".