Why do you think changes would be as likely to cause good as to cause harm? In complex, yet structured, systems - I think changes without fully understanding what you're doing are vastly more likely to cause harm than good. Software is the obvious example. Change a line of bytecode/assembly to something else. I think the chances of that change being good are extremely close to 0.

But in nature most mutations are neutral, period. It is likely to be more don't cares although actual improvements are unlikely. Good outcomes from random chances are rare but that doesn't mean that bad outcomes must be the dominant component.

Just look at Atomic gardening [https://en.wikipedia.org/wiki/Atomic_gardening] - a practice which should be /way/ worse if mutations really did produce bad effects most of the time. Instead the effects were either dud seeds or a few useful byproducts as opposed to 'this grapefruit is now rich in cyanide'.

This guy is 100% right, and this is important, so please stop downvoting him.

Unpredictable, therefore being dangerous and extremely risky?

They're often partners in crime, when it comes to subjects not well understood. Especially with something as fragile as DNA.