The word 'copy' is used by these guys in a very very general sense here. And it tells how much they understand the basics of aerodynamics and layouts.

A delta wing for example is used on multiple aircrafts, but the configuration of its layout makes/breaks everything. Now a person who has no idea of aircraft configuration would say.. Hey, you copied delta wing configuration from so and so... In most cases, even a double delta or a modified delta is called 'delta' by these "experts".

The motorcycle is just 2 wheels, a swing arm and a frame along with wheels, suspension etc. Good job telling people that all the motorcycles were copied from each other 😂

Physics... Learn a bit of physics first.