I tend to agree.
It's also worth understanding that horses are truly domesticated animals like dogs, they develop relationships with people and working along side them is something that most enjoy as long as they are well treated.
Although it's good to see harsh training methods become less used, I think there are a number of social trends behind this idea some people have that it would be better to not "force" horses to be ridden. One being something that affects people's thinking about human beings too - confusing stress with distress. All animals have times of elevated stress response and in some cases it's actually positive that there are times of rest alternating with times of more heightened response.
There's also an increasing lack of understanding of working animals generally, I see this with people who can't seem to understand that working dogs derive a lot of satisfaction from their lives, and that maybe the life of many pet dogs, even pampered ones, is pretty boring and unhealthy.
And related to this more and more people who want to treat all animals as pets. I recently saw a bunch of people in a poultry group jump all over a person who kept chickens mainly for tick control, because it meant they were out in the day and could be eaten by predators.
I'd also agree with you about people romantisizing a "natural" life. There are real wild horses where my husband works - their lives are very harsh indeed, they survive on tiny amounts of coarse grass, have huge parasite loads as you mention, often have to dig for water, and many die of exposure in the winter. It's illegal to interfere with them in any way, and yet somehow people don't think, oh, we have a responsibility to make sure these animals are cared for to a certain standard - quite the opposite they tend to think that the law is correct and they should be left to be wild.
There is a weird space between that being fine for one set of horses while another set are being abused if people want to ride them or cause them any stress.