I've used a spear on deer and rabbits, when it was legal in MN. But I don't how you would throw a spear out of any of the pop up blinds, just not enough room. So then you have to build your own? From my experience turkeys are fast reactors; so how do you learn to throw fast enough?
With a turkey close to a blind or even close enough while setup against a tree could be taken with a blowgun. Does that count as a spear?
I've killed squirrels with the blowgun by hitting them head so certainly a turkey would be killed with a head shot.
That CA self proclaimed "turkey psycho" is on to something using his .22 cal airgun. He hunts in areas where that is the only legal method to taking any game. He is a creative fellow indeed and I'm thinking about arranging an airgun turkey hunt myself.
If you agree with me call it fact; if you disagree - call it my opinion.
After all - we are talking turkey.