java.. lua.. jbeam... can we also add C++ and Ruby?

i'm sure there are reasons for this, and it must have been discussed before, but why is the game developed in such a hodge-podge manner?

im not trying to be disrespectful of the developers, but I'm just trying to understand if there are "historical" reasons why we're stuck with so many different programming paradigms, or is there actually a reason for it?