I have 400, and I made a living out of it for the past couple of years.
Sure, I was earning more when I was a freelancer. So, I guess his point stands, I am losing money in that sense. And if money was the only metric, he would be spot on. But money is not the only reason.
It's also true that most people just wing it, thinking they will make easy money online. And then, fail.
But well, guess what. Business is hard work. Any business. Creating educational material is not any different. A lot of work goes into positioning, copywriting, marketing, and sales. I would like to see his.
I know many people making excellent money with online courses. A couple of them are in the bi-weekly business mastermind I attend. Heck, if Apple didn't introduce SwiftUI two years ago, forcing me to re-do my courses from scratch, I too would be doing great, instead of just OK. But well, that's just "cost of doing business".
So, saying "you are going to lose money with online courses" is the same as saying "you are going to lose money if you start a business". I don't think that's a sentiment shared here on HN.