Why? Users can see HTML, why not Luan? I think it is a good feature. Users can hide code in the private section. If there is some page where the user wants to hide the source, say x.luan, then he can make a x.luan.luan to hide that.
This is a good feature if you want to build a hobby website or if making money isn't serious. In a serious commercial application this is a problem. HTML can be compressed and obfuscated, but the luan source can't (unless you have another tool to do that in the production server). So I still think we should have a way to disable that feature.