I always thought it seemed wasteful and unnecessary to cut off the crusts, but recipes always seem to add that step. So glad to hear from you food52-ers whose opinions I respect, that there's no good reason. Thanks!

why would you want to cut them off. If you have a meat grinder run your bread pieces through it, well as long as they have staled for a couple of days. It will make perfectly uniform crumbs without dulling you food processor blades.

I'm with AJ on this answer. I see no reason to remove them. There is an Italian proverb that goes something like, every crumb of bread you waste you must scoop up with your eyelashes before you can enter Paradise.

You don't have to, really, and in fact, if you have a nice bread with a fragrant crust, cutting them off is a shame. I'd only consider removing them if the recipe required perfectly uniform, fine crumbs. Even then, I'd probably process the crust with the rest and put it all through a fine mesh strainer. By the way, positively the best, most delicious bread crumbs are made with toasted bread. Tear the crusts into 1 inch pieces before processing, and start by pulsing, before running the motor continuously. ;o)