Tails are not bread crusts, lol. Our snakes have evolved eating whole prey animals- they need all the nutrients (minerals) from the bones (etc) just as much as any
thing else...they would not stay healthy eating "boneless rat wings" (if there was such a thing & if they were big enough). Even those pesky claws supply minerals.
So my answers are:
shocking? no; unnatural? well yes; unnecessary? yup! Detrimental? A big yes.
Now it's not rare for brittle frozen rodents to lose toes when jostled around prior to thawing, that's nothing to worry about. But I wouldn't remove parts intentionally.
Just because humans eat meat (unless vegan) & not usually the rest of the animal doesn't mean it's ok for snakes...we're omnivores & don't live on meat alone. Snakes get all their nutrition by eating the whole animal, & even the prey's GI tract supplies essentials.