We're glad it was Chell in there and not us, because we would have never lived up to GLaDOS's expectations. The test results would have been totally skewed, because we would have snuffed it at the first sign of acid pools or ricocheting balls of plasma energy.
Chell barely blinks an eye. Hell, she can probably solve any problem we throw at her. Maybe she can even fix our loneliness. Sigh.