The Software Carpentry team has stressed the usefulness of shell scripting for years [1]. One nice feature is that the scripts are easily tested as they are developed. For example, biologists find this approach helpful for constructing large data processing pipelines [2]. Because the scripts are plain text, they play well with version control (e.g. git). The tools are free, well tested, and will work on most hardware.
Go read "Mythical Man Month", written in your selected year of 1975, and see how relevant it remains today. It's pretty startling isn't it? That a book written over 40 years ago remains relevant today. Dismissing things because they're "old" is unwise. You just need to be able to separate the wheat from the chaff. Now excuse me while I get back to my "Speedcoding in 21 days" book... https://en.wikipedia.org/wiki/Speedcoding
Sometimes it is wiser to learn what has been tried, before reinventing what didn't work in the past. And tools that survived for 40 years in our industry can't be that bad.
A lot of the "modern tools" people use these days like git GUIs are just complicated fronts for their shell equivalents. Shells certainly are not outdated by any stretch of the imagination.
[1] http://swcarpentry.github.io/shell-novice/
[2] https://computingskillsforbiologists.com/