I agree, turkeys pay NO attention to popup blinds whatsoever! I can't count how many birds have been killed from my Double-Bull that I've had for well over a decade. Most of the time the blind was out in the wide open, I mean smack out in the middle of a pasture 50-100yds or more from the nearest treeline! Deer will spot blinds ASAP & take awhile to get used to them. Turkeys can't comprehend that that "camo box" sitting there today WASN'T there yesterday.
They aren't conducive to "run & gun" types of hunting but for hunting known strutting/gobbling & feeding zones, the blinds are unbeatable. Add in a comfortable bag chair & the fact that you don't even need camo, plus they are GREAT for hiding kids/1st time hunters who can't sit still, you just can't beat a portable blind for that kind of turkey hunting!