Compared to what?
The Japanese satellite, Hitomi, was an X-ray telescope that cost several hundred million dollars to build. The satellite was launched into orbit in February 2016, but mysteriously disintegrated soon afterwards.
Subsequent analysis showed that the problem was caused due to a series of software bugs. The satellite’s inertial reference unit reported a rotation of 21.7 degrees per hour when the vehicle was actually stable. The satellite fired of a series of counter measures to oppose the spin, which its software didn’t register, causing it to fire harder. The satellite spun around like a whirling dervish until it finally disintegrated.
Testing is expensive, compared to what? A series of simple integration tests could have prevented this software error from spiraling out of control. And the hundreds of millions of dollars lost could have paid for a whole lot of testing.
Most people don’t wish to pay for software testing, health insurance or a good bicycle lock precisely until the moment they most need them.