I think you need to read up on what a pyramid scheme is. You seem to have to serious misconceptions about it.
My personal understanding of "pyramid scheme" is something that demands you to pay something to enter, and what you pay go to those that were there before you. For the scheme to keep financially healthy, the number of people entering must never decrease. It's what Social Security would be if it was voluntary (as it's not, it's much worse, it crosses the line of "ethically ok" to "ethically wrong")
According to that logic, Worldcom and Enron were not criminal, they just exploited the stock market's ignorance about the true state of their finances. No ethical problem at all right?
I don't know what these companies did. Wasn't fraud involved? That's ethically wrong, similar to when Luke-Jr used people's computing power in a way that was not agreed upon.
If there was no fraud or violation of people's right than no ethical problem indeed.
You also manage to say something is ethically ok and disgusting at the same time.
Of course something may be disgusting and ethically ok at the same time. Being disgusting is a subjective opinion.
Anyways, we're getting off-topic. Let's try to remain on what happened here, please.