You might be pleased to hear Fred Brooks apologised for JCL in 2015:[1]

> If we had been smart, we would also have done a schedule-time mode of PL/I instead of doing JCL, the Job Control Language. But we weren’t smart. The worst mistake we made was JCL. Its existence was a mistake. Building it on a card format was a mistake. Building it on assembly language was a mistake. Thinking of it as only six little control cards instead of a language was a mistake, because it had no proper subroutine facilities, no proper branching facilities. That we did not see it as a language was the fundamental problem; we saw it as a set of control cards.

[1] https://cacm.acm.org/magazines/2015/11/193333-an-interview-w...