Well, I thought the thread mentioned about "regardless of genres". If we disregard genres...that's oboists - oboe being one of the hardest instrument to play! And yes, we do use oboe quite a bit in contemporary music, although bombthebasses is right that the keyboard usually replaces a real oboe. But then, a keyboard can basically replace every single instrument.
About the use of instruments in various genres (like what you mention, rock music), the choice is really dependent on creativity. Granted, an oboe (un-amplified) will be too soft in a loud rock band. But the reverse argument can also be true - it's not used (or tried to be used creatively) because oboe players are so rare. People use all kinds of instruments cross-genre creatively. 100 years ago, nobody can imagine a violin being used in a rock band, or an erhu being used in a pop/contemporary setting. Perhaps the reason we are not seeing certain types of instruments being used creatively enough is basically because they are rare.
Also in jazz, it's more than just the instruments you mentioned. There's clarinet (used quite often), trombone, vibraphone, among many other instruments. I would be really interested to see people trying to use Chinese instruments in jazz. Why not? And the challenge - a didgeridoo in a rock band, anyone? (another difficult instrument to play).
