He works every day at the corner of 6th and Pine in downtown Seattle. He's been there for years. He holds a sign that says (in part; it's a full paragraph long):
FRYE APT AND SEATTLE POLICE
YOUR COMMUNIST-DEVIL COMMUNIST LIAR!
He doesn't interact with the people that swarm around him on the sidewalk, but he shouts at cars as they pass. His voice is deep, gravelly, loud, and unintelligible.
6th and Pine Man has something very important to say, and he's absolutely dedicated to saying it. Trouble is, he's speaking his own private language. He's going to have a lot of trouble attracting supporters to his cause.
Here's another Seattle sign that's working to gain some traction for an important issue:
This is a yard sign you'll see often in my neighborhood. The organization behind it is Queen Anne Neighbors for Responsible Growth. A locally owned and much-loved grocery store faces being bought, torn down, and replaced by a national chain supermarket of the worst, most characterless kind.
You wouldn't know that from this yard sign, would you?
That's because like 6th and Pine Man, QANRG has chosen to speak a private language in public. In their case, they're trumpeting the philosophical underpinnings of the argument against the Big Ugly Supermarket. That's very sophisticated, but it's going to cost them support. Because the real issue is No Big Ugly Supermarket in our Nice Neighborhood! Even if you whole-heartedly agree with what the sign says (assuming you understand it) -- it doesn't lead you to any specific call to action that might galvanize opposition to the new supermarket. And that's too bad. Because it's a worthy cause.
Any time you're talking in public, take a moment for a reality check. Are you talking to those you're targeting? Or are you talking to yourself?