While I am fascinated by the self launcher, the sustainer and the like,
I have long been curious as to why a glider with a motor doesn't require
an "airplane, single engine, land" license to fly. *Just curious. *

Walt

because some bureaucrat decided it is a glider.........
and you can only fly it with a glider licence.
bureaucracy will never keep up with progress.

but in some country a touring motor glider is considered an ultralight
about as an "airplane, single engine, land"