Oh sure, this is bad but somehow when a group of people riot and destroy "public" property they are somehow just expressing themselves. Sure, these gun owners are destroying property they already own and will not directly take money from Yeti, but it does cause a public relations issue for the company and it will spread. This, will no doubt cause harm to Yeti's bottom line in the long run. This is nothing more then people taking a stand for something they believe in. Sure its not as sexy to the "left" as say taking a stand for legalized abortion, illegal immigration or nationalized healthcare but it still is a stand nonetheless.
In my experience, most gun owners are reasonably successful, fiscally responsible and crime free, thus destroying one of these coolers really isn't that big of a deal to them, otherwise they never would have spent the money in the first place.
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Why does it "irk" you? They are doing everything legally, at least as far as we can speculate here, they are not endangering anything/anyone, again as far as we can assume. Besides, who cares if it "irks" you, late term abortions "irk" me and there isn't anything I can do about it because it is a right, just like its a right to own and shoot a firearm.