This is a major flaw in decision making that some people have:

A new solution that has less problems is worse than an existing solution with more problems.

There's also a willingness to be less upset with humans making a mistake than a machine.

Edit:

Unknown problems may or may not exist so while I think that concern makes sense it doesn't matter until they come up.

I'm making the decision based on the current state. If additional issues come about then you reevaluate if the new solution is better or worse than the existing.

If you consider unknown problems then how can you make a decision?

X+Y > Z?

Where X is the weight of problems for the new solution, Z is the weigh for the existing solution, and Y is a value between 0 and infinity (unknown problems)