I agree entirely--but there's a line between trying to learn to be a vet at home, and learning some very basic first aid and treatment of very simple ailments at home.
You don't take the dog to the vet if it gets a little cut on its pad--you put a safe antibiotic ointment on it, and keep an eye on it.
If a snake gets an RI, we know that's serious--it should go to a vet (I don't agree with the folks who try treating that at home by nebulizing, personally). But, a minor case of worms isn't exactly serious if you catch it early, and the drugs used to treat pinworm or most protozoa aren't incredibly dangerous--panacur and flagyl have a wide safety margin.
We're considered competent to dose our horse, but not our snake. The procedure is the same--you weigh the animal, and follow the directions.
It's the division between livestock and 'pets' that I object to.