What does look like the native UI? I'm not a Mac user so maybe that platform has some uniformity? Windows is a total mish-mash and just about every app and utility for the past 20 years (even MS Office) has had its own "skin". On Linux, Gnome and KDE constantly redesign things, and every distro is different, so there isn't really a standard. The only things I can think of that are consistent are the utilities that come with the DE, but most of the apps I use on Linux are either browsers or IDEs, each with their own style, or console stuff (and even then, the UX varies!)
