Magsafe connectors aren't inherently safe - all the contacts are exposed, creating a short-circuit and fire risk. Apple solves this by only supplying power when the cable is plugged into a laptop. Counterfeit adapters don't bother with the additional safety circuitry.

If you were to poke the MagSafe end of a counterfeit charger into a wad of steel wool, you'd have a lot of sparks, and a good demonstration of why they're dangerous.

As for why counterfeits exist... basic economics. Third party Magsafe adapters don't exist, due to Apple's legal stranglehold on the concept of a magnetically attached electrical cable. In a field void of competition, unscrupulous electronics manufacturers see a huge upside, and here you see the result.

> What makes this teardown so dangerous inside?

There's an entire section called "What's wrong with this charger".

> And why would someone make a counterfeit teardown... mostly to get notoriety?

Why not?

Quality of output is definitely a problem for counterfeit. Also from the other page "The standards are somewhat incomprehensible, but roughly 4mm of distance is required between the two circuits." However likes like even counterfeit maintains that distance.