I think you have hit on an actual insight here, but it's worth noting that it's of an extremely similarly cynical and broad-brush character to what you're talking about. :)

So what you're saying is, everyone says something is black (or white to appear smart), so therefore to appear actually smart, I should say everything is a shade of grey?

Everything is a shade of grey Seriously though, most of the time it actually is, and it's almost always more complex than we realize.

Saying something like "Amazon is good" well, that's an opinion, definitely grey. Saying "This is exactly 1 inch", well, it probably isn't and the more you care about it's accuracy, the harder it is to measure. Most things are like that. Clear cut at first, and increasingly more difficult the more precise you go. The devil is in the details.

So, yes, if the only options are black and white, the answers are generally easy, you've got a 50% chance of being wrong. As soon as you blur the line, you're basically wrong all the time. The goal is to be less wrong, and to improve, make progress.