Whether you find web ads intolerable or not is surely a personal matter. I
certainly do, in part because thanks to amblyopia my eyes are rarely
pointing in exactly the same direction: if one has unwanted flashy blinky
brightly coloured adverts in its visual field, it'll completely drown out
the text visible in the other eye's field.
Other people may just dislike the attention-grabbing flashing, or perhaps
just think they're tacky. :)