“I might be missing something here, but how is the source code "visible to all"? You need to decompile a bunch of classes with obscure names to see the source code.”

s/obscure/obfuscated/. They aren't even obscure until you de-obfuscate.

Minecraft source is hardly any more visible than Photoshop (they both just have to be decompiled). It's just a bit simpler to work with :B. When [if?] Mojang finally releases the source to mod developers (as promised a while back) these statements will become valid.