gross!Because they stink (and, according to the info on the site I linked to - some stink more than others). However, our chickens and turkeys ignore dried meal worms. A lot of feed preference is `learned' early in life usually transmitted by food choice by chicks' hen. Ours got moths, grubs, earthworms, watermelon and grapes (fed by surrogate human `hens'). Our neighbor's turkeys and chickens destroy their tomatoes - ours just growl at tomatoes tossed in the run (didn't encounter them until they were nearly a year old). Could be the other chickens that eat these well armed beetles were `taught' to eat them - `kinda nasty.. but protein, kids!'.
You might consider setting up a meal worm `farm' and `grow your own', this is much cheaper and there are numerous threads on BYC about every aspect of meal worm `replication' and management. Also, IIRC, growing up in San Berdoo, myself, there were lots of moths around the lights, most of the year. You can place a white sheet in front of strong incandescent light and go out and harvest all the flying, fluttering snacks that land on the sheet, bottle them up and start tearing off the wings and tossing them into the run the next morning.