Why do some people insist on putting human emotions onto animals?
I've owned a dog (save the mandatory year or two mourning period after each passes) non-stop since I was a little kid. I'm 62 now.
One thing I learned many decades ago is that a dog doesn't experience human emotions. A dog experiences dog emotions, all based on pack behaviour. (And don't get me wrong, I love my dogs - even though they love me back for a very different reason than why I love them).
The horses that pull carriages are draught animals, bred to "pull things". They don't "love" pulling things, nor do they "hate" pulling things. They just pull things because that's what they were bred to do.
They're not people, and pulling things isn't "work" to them ... it's instinctual behaviour bred into them over centuries.
What draught horses really like is to be fed, watered, brushed, and to experience human interaction with their handlers simply because most breeds of horses aren't loners, they prefer to associate in groups whether those groups consist of people, other horses, or a combination of both.
I get that these "anti draught horse" folks are projecting the concept of "horse-rights" onto these animals, and that Isitt is pandering to his base by putting forth the optic that he believes that all living things must be "free"... but in many ways sticking draught horses into a farmers field, and retiring them from doing what they were bred to do may very well be more damaging to the horses psyche than pulling a carriage around town in return for a bag of oats and a drink of water.
Because a draught horse pulling a carriage around in return for a bag of oats and a drink of water is living exactly the life his well developed horse brain tells him is the perfect life for him.