I'm not a huge fan of brown leather, but Calendar's textures work together to draw my attention to the most relevant parts of the screen in a way that is almost entirely missing in Google Calendar, to pick on a prominent competitor.

The leather is mildly ugly if I focus on it (never), but Google Calendar's harsh asymmetry, nonsensical color scheme (cartoonishly highlighting two buttons - "SEARCH" and "CREATE" - I never use), and inability to hide numerous unused elements bother me every second I have the tab open.

I don't understand the value of these discussions about design that start and end with how skeutomorphic an application is. It's one of dozens of design elements, and it's disappointingly rare to find a well reasoned argument (not "I dunno, Windows 8 just feels cooler now") why skeutomorphism is categorically bad design.