Have also been doing the course. It actually has a lot of useful content and you don't have to agree with them. I like the stuff about spending intentionally on what you value, avoiding lifestyle creep, and consciously examining your money mindset.
It has actually made me think properly about everything and my choices and life and, ironically, decide to spend more now, rather than anxiously obsessively saving and feeling guilty at every purchase beyond Lidl basics (life events and circumstances kind of miserably got me to that point).
I do agree that it's obviously very different for me and for them given our different lives and circumstances, but it's still helpful overall.
I still don't buy into the idea of investments because they are volatile and I'm risk-averse, but let's see what I learn from the later weeks of the course.
The whole thing so far has been psychologically useful to me and made me look at everything with more clarity and honesty. Haven't read this particular article but they don't come across as smug etc online...the course is free, no upselling, and so far they come across as congruent and genuine.