I have mixed feelings on this. I don't see a problem with keeping a cat indoors only and I also don't see a problem with having a cat being indoor/outdoor, depending on the neighborhood. Living in the city vs the country makes all the difference.

What I can't imagine is why someone would make a cat stay outdoors all the time though.

The cats at my parents house are indoor/outdoor. My parents live out in the country and there is not a lot of traffic. Our first cat, Sable, lived to be roughly 15 and he could make a grown dog wet itself. He guarded his territory viciously, but was one of the most loving and loyal cats I had ever known. He was about 8 when he adopted our family from a life as a stray.

Mom has horrible allergies and asthma. Even with all the medications in the world, letting the cats go outside for a few hours helps her breathe.

Our boys are big and healthy and those that are getting up in their age spend more time indoors than out.