But repeating failed experiments has the same scientific value as repeating successful ones -- it solidifies the result, increase our certainly about it.
In real science, null results, and their replication, are extremely important. My favorite example is the Michelson-Morley experiment that expected to find differences in the speed of light due to the motion of the earth through the hypothetical ether.
The failure of this experiment, its publication, and efforts to replicate the result, also dutifully published, finally created a revolution in physics when Einstein explained why there was a null result, and coincidentally gave birth to the modern world.