https://www.physicsforums.com/insights/why-we-dont-discuss-perpetual-motion-machines-pmm/

The Meaning of impossible in Natural Language The human spirit requires that we reject the word impossible. Any coach in a locker room pep talk tells his team that it is possible for them to beat any other team today. Our most celebrated inventors make the impossible possible. Delivery of a terminal prognosis to a patient is traumatic, so we frequently present undue optimism and say that survival is possible. But there is a difference between what we might call Impossible (with a capital I) or merely impossible (small I meaning difficult). Wikipedia says it well. “Epistemic impossibility” describes things which absolutely cannot occur within our current formulation of the physical laws. This interpretation of the word “impossible” is what is intended in discussions of the impossibility of perpetual motion in a closed system. For clarity we simply use Impossible with capital I for A, and impossible with small i for B.

http://hoaxes.org/comments/papparticle2.html

 

Because they are too close to religion and always end up in flame wars.

 

I believe that jpanhalt's explanation is correct.

A simple way of looking at it is that the subject is prohibited by the User Agreement.

https://www.allaboutcircuits.com/user-agreement/

Restricted topics. The following topics are regularly raised however are considered "off-topic" at all times and will result in Your thread being closed without question:

• Any kind of over-unity devices and systems
• Devices designed to electrocute or shock another person
• LEDs to mains
• Any kind of jammers (ie - Phone jammers)
• Rail guns and high-energy projectile devices
• Transformer-less power supplies

 

Hello,

There was a thread in 2009 about the issue:
No more HHO, overunity, or Meyer

Bertus