COBOL was created 1959. Singly it out as an example of a DSL in this context is a bit like arguing against cars by pointing out the faults of the Model T Ford compared with a Tesla. It just isn't a very good or fair place to start the argument.

I'm not arguing, of course, that we should go back to using COBOL. But lets get the facts straight. By 1997, according to Wikipedia, "there were a total of 200 billion lines of COBOL in existence, which ran 80% of all business programs." It was, in other words, a massive success. How does that prove that DSL's are no good?

It's a little hard to wrap our heads around the state of computing in 1959. I'll just say that at the time it was a difficult even for academics at big universities to get good access to computers. Most of the readers of this site weren't even born yet. Yes, of course, COBOL's out of date. If it weren't that would be a miracle.

DSL's may or may not be a good thing, but bringing up COBOL is perhaps not the most effective way to reach a valid judgment on the subject.