I think this is where the confusion is. People aren't saying to substitute God's wisdom with man's, to not listen to God at all and only man.
We are to rely on God, to come to Him. But He put the body of Christ together for a reason. And I don't know about you, but I've learned (good) lessons from non-believers as well. Sure, I may have to measure what they say and hold it in more scrutiny to see if it aligns with the Bible, but advice, encouragement, comfort, guidance...those can all be found in other people. Should it be found only in other people? No, and no one here is saying that.
Something else to keep in mind...and I'll make it personal so as not to project, but I'm sure others have felt the same:
Sometimes I need OTHER PEOPLE to get me BACK to God. In a perfect world, I would run to Him every time. I wouldn't struggle with who He is. But the reality is that I've run to other Christians first because I did NOT want to run to God (for various reasons, I can elaborate if wished) and they have helped me through it and/or set me on the right path towards Him.
Furthermore, I know some very VERY wise, godly people. I would not discredit their wisdom because "Well you're a human so your wisdom stinks, I'll just go ask God." Have you (general you) ever considered that maybe their wisdom is God's wisdom coming through?