Whenever I read that meme I get damn suspicious about why java code isn't valid groovy code in all cases. Why only most cases? It all sounds like a recipe for spending half a day debugging simple scenarios where things don't run as intended.
To be taken seriously (or as seriously as a language called Groovy can be taken), embrace and extend Java fully, don't embrace only 99% of it before extending. That's what Microsoft tried with J++ and lost a lot of trust with developers that took them a decade to win back.