This simply isn't true (Unless you simply meant all the shoes you've tried yourself). On my mountain biking shoe, the metal cleat is clearly the lowest point, and makes contact with the floor. So when I walk around I sound like I'm wearing tap shoes.The cleats on my touring SPD shoes, OTOH, are tucked up in the sole enough that they do not touch the floor when I walk around, they make no sound.

Also, the contact area between the shoe and pedal varies from model to model. If you look at Crank Brother's Egg Beater pedals, there is nothing on them to contact the shoes beyond the retaining clips. Or the ubiquitous Shimano 520 style have about 0.5 square inch of contact which fits neatly within the recessed area around the cleat, not making contact with the walking surface.

Seems you could find a better shoe/pedal combination that the ones that you describe having trouble with.