It's worse when they are right though. I wish I could say that had not happened to me.
What I find is you start with several viable approaches, pick one and go down the path enough to figure out the downsides. At which point you need to decide to backtrack or keep going. That’s the hard part not simply coming up with a seemingly simple solution.
These groups are not mutually exclusive, membership can only be assigned by a domain expert and is finally irrelevant if the other is right.
(Somewhat frighteningly, two of those people are doing that at Facebook right now...)
Generally when one is very close to the problem, one sees the environment as immutable. Because, well you spent very many hours building that environment, for very good reasons. And your complex solution "has to" work within the constraints of that complex environment.
Whereas, the "mind of a child" that doesn't grok the environment, also doesn't have a fixed notion of it. This is anecdotal of course, but maybe half the time what I see happen is that it's easier/better to change the environment and this can only be seen with fresh eyes.
It's not the spoon that bends, and it's not you that bends around the spoon. There is no spoon.