Lua scope global by default, why?

[Anticept <anticept@...>]

Good Day everyone,
  I would like to ask why Lua scope is global default? I have tried 
combing the message boards for a reason as to why this is set to work 
this way, but to no avail. I do not mean any insult to anyone, but isn't 
this a bad practice, especially for an embeddable language? With many 
games using this language to allow customization and modification to the 
game itself, I find this becomes prone to errors, particularly for new 
programmers.

  For example, the game "Garry's Mod" uses Lua to create the tools and 
functions of the game to interact with the environment. However, often 
many new and experienced programmers alike sometimes overlook scope 
during the course of their programming, and this creates subtle 
conflicts that sometimes break down the game experience. Also, very 
often, as many modifications are installed to the game, these subtle 
conflicts can cause catastrophe, and make bug squashing very very 
difficult, as by themselves, these modifications work flawlessly.

  Is there a possibility of Lua moving away from this? Or perhaps, 
allowing the embedding programmer to change the default scope?

  I thank you for your time! :-)
  -Corey