[istjohn]

People who have ADHD are used to being told they just need to stop being lazy. They already have to overcome a huge stigma to seek diagnosis and accept treatment. So, yes you are being "antagonistic towards...people on the basis of their membership of a particular group." Your solution seems to be that instead of seeking scientifically validated treatment that has already helped millions of people, they change the socioeconomic system they exist in, in which they have to work a 9 to 5 to provide for themseleves and their families. This is not practical advice. So not only are you peddling medical quackery, but you don't even offer a snake oil alternative to the audience you're demoralizing.

You also create a false dichotomy in which either modern society fails in certain ways to meet all of our needs to the detriment of people diagnosed with ADHD, or ADHD is a legitimate mental illness that benefits from pharmaceutical and therapeutic treatments. Both things are true.