That's an extreme nitpick. The whole argument for time shifting is to be able to record something while you're not at home.
Honestly I don’t know why VCRs are so hard to program but all of the buttons can’t help. I might be getting old but the Roku remote seems about right as far as complexity in the device goes and I can see how a nice interface with relative timekeeping could do what you need without a clock per se. Inertial guidance for timekeeping? A self winding DVR?
Two things off the top of my head that I can think of: 1) knowing that a blinking number is indicating some kind of selection and more generally 2) seeing the UI as a glimpse into a larger abstract space that can be navigated. Or in other words, having used computers for many years, what my parents sawzl as just a blinking word, I would see as a menu where up/down/left/right had meaning.
There's also some more abstract thinking involved there - for me it's very spatial so I think of it as being able to keep track of your place in this 'abstract map'. You had to learn some non-obvious things like "if the down button stops working, it probably means I'm at the 'bottom' of my available choices" or "if I start seeing the same choices again, it means I have 'wrapped around' and in a logical sense I'm back to where I've been before".
I actually remember thinking something like this as a child when we got a VCR. I think I remember that realization that "this is a menu I can explore". The exploratory skills you pick up when you have to figure out how to use something technical generalize really well to other technical things.
TL;DR: I think VCRs were hard to program because the limited UI of buttons and a tiny screen meant that you actually needed a fairly built-up mental model of the process to keep track of what you were doing.
The biggest “what were they thinking” part for me is why they cram a whole GUI with config options and menus into a clock when almost every use case for a VCR is already connected to a perfectly workable display which is much better suited to a GUI in the form of the TV. Later VCRs had onscreen rather than on-device GUIs but by then institutional momentum was too far along to redesign the remote when they moved the GUI out of the device and onscreen. Truly a missed opportunity.
I don’t know anyone involved in any VCR product. If I did I’d be asking them a lot of questions. But I have a hard time thinking they meant to make it so hard. They probably were clapping each other on the back and congratulating each other. They were inventing future ways of using content and for that they deserve praise. They just sucked at understanding how hard it is for non experts to put themselves in the mind of experts, someone whose inner mental world has jarringly different contours and whose mental model of reality may have little to no correspondence whatsoever with their own.