Well to be fair, their picture is of a taco supreme and it looks like you got the normal taco.
I found that the shells weren't very powdery when they first arrived, but after a couple of months they changed to be more like an actual Doritos. I also found the fiery ones to not be very spicy.
Doritos tacos are one of those dumb guilty pleasures I like every now and then (much like taco bell itself).
Though the other day I did find myself buying a bag of Doritos and a couple 2 liters of Mountain Dew and then had an "Oh shit, I'm part of the problem" moment lol.