I think people just don't get the impact.
All of the "well just be stricter, just tell them, my kids respect me" stuff. Have you never experienced anything that scares you and makes you feel overwhelmed? Like how some people love rollercoasters but for others they're horrific, or jumping out of a plane, or being shut in a room full or snakes or spiders. Some people would be fine with any of these.
School is like that for DS, the noise, the unsureness, not knowing what's going to happen, where he should sit, if he will have to speak, if a classroom or a teacher has changed. If suddenly the topic they were supposed to do they're not doing because they've got a cover teacher in. For him, it's like having to stand at the door of a plane being waiting to be told to do a parachute jump he doesn't want to do, every day, 6 hours a day, 5 days a week. Would you put your child through that? Even if it seems a stupid fear to you, people who like spiders probably think thats a stupid fear for others too.
He is bright and wants to learn, in therapy one of his biggest worries is not getting an education and how that will impact his future.
But no amount of strictness is going to make him feel less terrified. We're working on the fear with therapy to try and make life more manageable for him, which is a reasonable way to treat anyone, adult or child. Forcing a person to do something that makes them feel so scared they're sick, over and over again isn't "good parenting" it's torture.