All this seems like circular thinking to me and it's giving me a headache. 
I'll make it simple. Here's the original question again:
Now, supposing that there was no link proving the nonexistence of Bigfoot, do you believe it really exists? 
My answer, yes.
Thank you.
Yeah, it's a convoluted web we've woven (hmmm, say that real fast 5 times) but if you were hurtin', short on sleep, and high on pain pills then you might be typing whatever is rattling around in your melon just to help pass the time, too.
"I swear, it was the DRUGS that made me do it!"Thanks for playing along.
Just how would you prove the nonexistence of something though?
Exactly! Good one.
I just threw that in there as a joking reference to your Simpson's/Springfield link, which basically debates the whereabouts of a two-dimensional cartoon family that doesn't exist... or does it?
Reminds me of when I got audited by the IRS some years ago. The IRS agent wanted me to prove my wife's ex, who had been deported when they divorced and we had no contact with, didn't give us any child support. When I asked him how I could do that, he said, "Nevermind, I see your point."
Wow, the IRS conceded a reasonable point? Amazing.
Oh yeah, Bigfoot. I wonder why there have never been any bones recovered? I mean, we're digging up dinosaur fossils millions of years old (if you answered "E", that's for you) yet not one scrap of physical evidenced confirmed as from an unknown giant biped. We even have fossils from that "Austro-something Gigantus" giant ape that lived in China thousands of years ago.
You'd think that a large enough population needed to support itself all this time would leave behind
something of itself besides footprints.
If a bigfoot exists on this planet, the most likely candidate would be the Yeti in the Himalayas. That's a very harsh and remote environment where something that big and well-adapted to the conditions could possibly hide from the curiosity of man.
The Pacific Northwest is also a vast wilderness, I've hiked and backpacked miles and miles in Washington, Oregon, and NorCal, and there may be enough room to hide... but for a whole species of large mammal? They must be very meticulous about where they poop, and how they dispose of their dead. And they must eat a lot of slugs...
If a race of Bigfoots exist, I hope we never find them. The mystery would be gone. And most rare species or remote cultures don't fare too well once us humans start "helping" them.
