Why do people think it's such a horrific idea to let a cat outdoors?

[john]

Besides the other reasons that were mentioned.Another reason to
keep you cat indoors is to avoid cancer causing chemicals that's
used to promote healthy lawns.Oh yes and don't forget about
the outside insect prevention pesticides which are loaded with

toxins.

[black_lottery]

yes their ancestors may be out doors but not the domestic, number one a coyote wolf bird or other dog could kill the cat, including getting hit by a car or someone getting mad its on their property and shoot it or call animal control. They could get fleas worms or anything else. CATS belong inside not outside like lions