For a great many people, 'I'll stick to chickens' is exactly the right thing to do. Exactly.
Horses are large, expensive, require land, fences, housing, frequent attention from a trained farrier for their feet, none of which is cheap, and for most people, it's been many generations since they had any contact with them, and they know virtually nothing about them.
Horses are most likely THE most mistreated, neglected, misunderstood animals people get. The bigger the animal the worse it is when it goes wrong.
It is not expensive or burdensome to learn how to take care of a horse. The rules are simple and easy to learn. There are not that many of them. Most of them are simple commonsense.
A person can volunteer at a vet clinic, a rescue, a therapeutic riding center. They can pick up a book and read it. Most public libraries have shelves and shelves of books on how to care for horses. They can pick up free brochures at their vet's. They can go to their extension office and get tons of free information. They can attend free seminars at vet clinics, riding clubs etc.
With a very very simple tools a person can care well for their horses. It takes only a minute or two to learn to take pulse, respiration and heart rate - cheap stethoscope to listen to the heart can be had for sixteen dollars.
The information is out there, largely for free, for anyone to learn who is willing to make a very small amount of effort. If they are not willing to make the effor then they shouldn't get a horse.