Maybe it’s just that Blair is so old school that he figured if he was the last man standing at the camp he would hang himself before he could be copied.

Also, regarding the 2000’s prequel my main objection is to the melting two faced corpse that the Americans find in the original movie. In the newer movie it’s a very graphic scene where the one Thing mashes his face into the other guy’s. That’s not how I ever pictured that Thing being created. The original artists clearly mean it to be a single melting face and the new movie changes that for this far less “believable” reason.