[magicalhippo]

And a terrible programmer can cause a lot more problems than they solve...

Both programmers and CEOs (and others) can be "force multipliers". If they're really good, they can help their company do better than the sum of the parts.

If the programmer is mostly working on code it's usually easy to discover if they're detrimental. Though if they're doing more fleeting stuff like design, it can be more difficult because the effects are less direct.

In a similar way, a CEOs performance can easily be masked by other factors, such as the market in general and good employees. Say the company increases sales by 10x, but most other candidate CEOs could have done 20-30x or more.

That said, I do think there's some other factors at play when hiring CEOs, as some with known repeated terrible histories still get hired etc.