It means no such thing. What it means is: 1) You're trying to
'invent' in a field that you haven't a clue about the current state of
the art of, and 2) Because you usually come up with some really
technically ****ed up way to try to do something we already know how
to do if we want to, you just waste everyone's time.

I said I feel good about my invention regardless of its first discovery status. The MHD motor is the true genius.

My invention is technically an abstract "fountain" of fuel ions. Focusing on the motor chamber with multiple lasers is viable also. It would also be possible to carry fuel along also. The fuel could be something like hydrazine for a hybrid fountain motor. The chamber can be a burning normal rocket motor. This would allow boosting at higher altitudes. If the fuel was like Freon, the laser would have to do ALL the plasma making.

The allowed flight path, other than straight up exists I believe. An asymmetric ion emission could give an orbital velocity. In fact a second motor could be added where the side of the rocket has an open view port. Giving a change 90 degrees to full orbital acceleration. But this must occur in the atmosphere.

Thereby defining the usefulness. Can it accelerate to orbital velocity by 100K feet of altitude? This basically only defines a minimal power level.