These upvotes prove that there is opportunity for products to be clever, but not simple. For every windows like product, there is an opportunity for command line tool.
Clever but not simple? I have a hard time believing that people want to sacrifice simplicity for cleverness. But I see your point about people preferring a CLI than a web portal. I guess simplicity is in the eye of the beholder. What's simple for me, can often be wizardry for my dad.
At the risk of facing the wrath of developers, they also choose products that are not are not necessarily clever, but makes them clever. e.g: IaaS Vs PaaS, C++ Vs Visual Basic etc.
Developers usually say that abstraction doesn't give them enough control/flexibility. That might be true in some cases. But in most cases, they are afraid that abstraction will make them dumb, instead of making them clever.
I think that's a stretch. I like the calendar, but from what I can tell it's only useful for looking up the day of the week that a date falls on; shrinking it like this is similar to lossy compression.
With a moderate amount of practice you can also calculate a weekday given a date in your head! (Though I'd rather use this w)
So this is not exactly a "product"; people wouldn't fork over money for this. It's a neat design concept.
To add: CLIs aren't necessarily clever (I'd add rarely clever), and Windows-like products can often be far from simple. There are learning curves involved, but I think that's (mostly) a separate matter than simplicity/cleverness.
Again I think this calendar is cool, props to OP for thinking outside the box and making something for the new year~