@FailForwardCool, thanks! I shall look in to all of that! :)
But yes, I know what you are saying. In all actuality I use "all" the platforms. At work, which is very locked down for security reasons, I'm on Windows. I'm typing this on my 5k Retina iMac and when I'm talking about cli tools for Linux (Manjaro in my case) that is my second machine next to this one, which mostly handles everything in my home when it comes to media serving etc. I wouldn't dream of doing photo/video/design editing on the linux box; that is WHY I have the iMac in the first place. :)
However, I do like challenges, and I am aiming to get to my old dream machine I used to have at work, but in a smaller version, which is basically a minimal (Manjaro) Linux install, based on XFCE but using Xmonad for windowhandling. That means I can run "regular" desktop apps, should I choose to. But it looks so much cooler with an all-out cli view. Also, it fills my need for tinkering and problem solving that is "outside" of my regular problem solving (work/family related etc).
There is also a privacy/security reason behind my tinkering, and like you say, I have started falling back more and more to "the basics". Getting fed up with "productivity tools" and their flaky-at-best or privacy-intruding synchronization between platforms, started falling back more and more to things like "why don't I just use git?" and "hey, I can actually store both Notes and Todo/Reminders on my IMAP account, and they get picked up by my iOS devices as well as my wifes Android!".
I have been looking at Taskwarrior and have yet to decide if I should go down that route (as it doesn't strike me as cross-platform portable) or if I should go down Todoman (which saves todo's in ical format) etc.