some people who opened boxes in the store to check for bright spots, might not have actually been seeing defective devices.
i left my protective screen sticker on until yesterday, and i occasionally saw bright pixels but if i peeled up the sticker in that corner, they disappeared, so it seems if the smallest amount of dust was caught under the sticker when brand new, it will appear to have such pixels before the sticker gets taken off.
of course peeling up and putting back the sticker just made more dust get caught, which is why i finally decided it was stupid to leave it on or buy one to protect the screen, since it would be impossible to put on without something getting caught (well for me it would anyway).
now that the protective sticker is gone no sign of bright pixels.
i wonder how many perfectly fine devices were rejected by customers who were worried about bright pixels.