Yeah this is a good decision by Valve in my opinion. Say you have a product on a grocery store shelf, and they have a sticker where your product is that gives the wrong price or something.
Yes, it may impact sales of your product, but if you curse and yell and threaten a company, they will cease doing business with you. Imagine walking into a room with suits and threatening them, then being surprised when they no longer want to carry your product. Heck, you may even be arrested and sued.
He could have easily followed proper procedures for having the error corrected.
Business is, and always has been, best done by professionals. So if you can't act as a professional, sooner or later, you will see the consequences.