1. X11/X.Org make precision monitor support (especially DPI) a royal PITA 2. Perpetually broken video card drivers mean basic acceleration can't be relied on.

1. X11/X.Org make precision monitor support (especially DPI) a royal PITA 2. Perpetually broken video card drivers mean basic acceleration can't be relied on. 3. GTK and Qt just don't have the polish of Metro or Cocoa. I think both are prettier than Win32. 4. The comparison isn't all one-sided: Windows definitely has its rough patches too. It's making improvements however so Linux has no room to be complacent.