I agree. I think what the author was trying to say with his article is that DSLs where end users can use the system with zero training are a hoax. You can't put SQL, LateX or even Excel in front of someone with no context or help and expect them to understand how to use it. But with a few days or weeks of training, a business user can go from being helpless to being able to query their organization's database and create fancy charts.

Much like most things in software, it's key to hit the correct level of abstraction.