What's the # 1 reason to disbelieve the existence of Bigfoot

The way I see it... there would likely be a fair amount of them by now if they existed to where people would have likely found something solid by now. it just seems quite unlikely they would be as obscure as they supposedly are if they have been around a while as their population would likely grow and people would likely start spotting them more often etc, especially in today's world where just about everyone has a cell phone/camera. I am sure you get the gist of it

so while I am sure some people can easily make crap up for fame or to keep the legend alive etc, what I said above I think is a pretty strong reason against them existing.