It's good of you to be concerned about the dragon's well-being but it sounds as if you’ve been greatly misinformed about mammalian proteins and dragons and the concept of moderation. The term moderation really means just as a supplemental food source. Some supplements are given more frequently than others and mammalian proteins are definitely down towards the bottom but that doesn't mean they are not necessary or unhealthy.
It's not that responsible keepers are trying to mimic the actual prey eaten in the wild but rather we are trying to approximate the nutrient composition. In the wild, bearded dragons occasionally eat rodents and small lizards. They need the calcium and other nutrients present that are not found in invertebrates. This is why we dust insects with calcium powder, to make up for this lack. "In moderation" doesn't mean that rodents are horrible for bearded dragons and you can only feed them a little because it's poison but rather that they only eat them occasionally and that's all that's needed for a well-rounded diet. Dragons love fruit but it wouldn't be good as their primary food source.
All dragons can benefit from an occasional rat pink. Breeding females greatly benefit from them for both the added fat reserves and the calcium for egg production. Does that mean you feed breeding females an all rodent diet? Absolutely not but occasional pinks or fuzzies are very beneficial. There are health risks from overfeeding rodents, such as fatty liver disease, but that never happens if you feed them appropriately as an occasional supplement. Waxworms contain a lot of fat and are great occasional treats. Superworms are good occasionally but I can't count the number of emails and messages I have gotten from owners who tried to give them as the primary food source and don't understand why their beardie keeps vomiting them up. Phoenix worms and hornworms are great as supplemental but not primary feeders. Small rodents are just another item in this supplement prey list.
Now, with all of this said, I don't agree with feeding live adult mice to dragons because bearded dragons cannot immobilize them quickly enough to prevent damage. I agree with that part of your post that this is an irresponsible practice. However, feeding f/t or live pinks and fuzzies as an occasional supplement is absolutely an appropriate food item.