Leave your weapons or walk your choice.
You are absolutely right. The airlines are private firms and they can make the rules on their private property. So I seek alternate transportation whenever possible. I've cancelled business trips that I've suddenly decided could be accomplished via internet/phone/conference call.
Now I've only got one problem with "playing by their rules". Where does my government come off taxing my money away from me, and then giving it to them? If I'm choosing not to play, why does the goverment keep anteing up with my money?