That was mean. lol! And, if your silver bullet doesn't hit the right spot, what then? Tracking a wounded Bigfoot through presumably very thick woods, seems like a worse idea than even shooting one in the first place.
By the same token, many thousands of very large and dangerous animals (including humans) have been captured alive (Lions, Polar Bears, Elephants, etc. etc.). Yes, Bigfoot are likely much more intelligent than those animals, but those animals have other mad skills that humans have overcome, for instance, a polar bear having a sense of smell 7 times better than a blood hound. Hey, if a kid riding a cow can lasso the moon then, what chance would a Bigfoot have?