Also, users have certain expectations about OS chrome. Now Windows is already a big mess, so whatever, but one of the things that allow you to work with any application you never used before is because they tend to stick to conventions. Also, Windows won’t look any better if every application has custom chrome. In fact, if you really dislike the default looks of Windows, having that application-specific custom chrome just removes the possibility of system-wide ui customisation. Really, application specific chrome makes no sense, is not a good idea and should not be encouraged. That you can, perhaps would even like to do it, and that others are doing it, are not good reasons for a project like Atom prioritise such things.