Yeah you are right, Maico didn't win any World Championships. That is probably because they couldn't afford to buy the Championships like Suzuki and Yamaha did. The bikes Joel Robert, Sylvan Goebers and Roger DeCoster raced were a lot lighter than the production Maicos, but still they finished next best to those riders.
But clearly I won't convince anyone who doesn't really know Maicos of how good they are, so you might as well just remain ignorant.