This might be a joke – I can’t tell. But this newspaper article quotes a gym climber about the problems of climbing outdoors:
"They should have signs and stuff and trash cans outside," said Pham, who climbs regularly in the safety of a San Francisco gym. "I don't think they even clean your rocks off for you out there."
It is confusing climbing outside since there is no tape on the holds. And the rocks get dirty and won’t stay where they are supposed to stay. And it might rain or be hot or cold.