The only thing I see wrong is they say a circuit is only rated for 80% of the available current (based on the OCD I suppose). That seems to ignore 240.4(D) that builds the 80% into the allowable OCD size. A properly wired circuit should not be a danger at any load within the OCD capacity. The receptacle itself might not be up to the task of carrying all that current in one plug but U/L tells us it will fail safely, containing the fire in the box. If the load was divided across a few plugs I don't see a problem for the building wiring at all. The real hazard is on the load side of the faceplate. All of those skinny extension cords and counterfeit listing cube taps are generally where the fires start.
It's hard to find a really well written article on electricity that is intended for a non-technical audience.
Most people will get the point of the article though:
Don't plug too many things in one receptacle.
We can find errors and ommissions in just about every document ever written on the topic of electricity and the NEC. TV programs are usually even worse.
Just look at all the bad information that has found its way onto these forums over the years...
Bryan P. Holland, ECO. Secretary - IAEI Florida Chapter