Quote from jamolnng
Obfuscating provides an extra layer of security to the code. As a programmer myself I prefer my code to be my secret, it keeps people from from stealing it (I don't obfuscate but I use C++ mostly and most people can't interpret machine code).
That makes sense if it actually worked as a security layer. As it stands, with MCP and whatnot, it doesn't work as one. The fact that Mojang hasn't tried to take down MCP and even kind of works with the MCP guys shows that they don't mind people having access to non-obfuscated Minecraft code, in which case the question becomes, why don't they just cut out the middleman and provide it themselves? It would make the jobs of a lot of people within the modding community a million times easier, and MCP would have no real reason to ever be updated. That's the only thing that comes with MCP updates, except for the very rare bugfix here and there.