This reminds me of an article I found recently while trying to explain to a business analyst that the problems we are solving aren't simple. https://noop.nl/2008/08/simple-vs-complicated-vs-complex-vs-...
I think what is bad is confusing complex and complicated things for simple things. If you think a problem is simple, when it is complex or complicated, then you'll expect the solution sooner and you won't think deeply about all the ramifications of the solution. You'll avoid breaking the complexity down into simple parts.
By their nature, complex things are unpredictable. Things that behave unpredictably are complex. It doesn't make them bad, just means they need more attention and thought to understand -- and sometimes accept.
Another good resource I just discovered is the Cynefin framework that breaks it down further: https://en.wikipedia.org/wiki/Cynefin_framework
> obvious, complicated, complex, chaotic, and disorder