Why no public class fields?

[ariankordi]

I noticed that Fusion doesn't allow class fields to be marked public, with the only other option being to make getters/setters for every field.
I realize it's best practice in OOP to use getters/setters, though it's still perplexing to me and I'm trying to understand why this restriction is here.

My main concern with this is just code size, in my case porting a C struct-like object that has dozens of fields that I want accessible externally (parameters for a character creator)
In C/C++ those getters/setters are often inlined, the problem is I don't think you can do that in JS, especially when private fields need polyfills that otherwise wouldn't let e.g. Closure Compiler optimize them out.

I'd appreciate a more thorough explanation or rationale for this, thanks.