I think the author of the article is describing a false dichotomy. The purpose of deliberate practice is to build the underlying knowledge that leads to the creativity and also unlock the intuitive sense that comes from mastery.
There are multiple different psychological theories that might explain why we dislike code that we don't write. I do agree it is an interesting thing to think about.
Two that I can immediately think of are
1. Ikea Effect(1) - We place a higher value on things we create vs. things we didn't create
How it applies: We place more value on code we wrote compared to what others wrote.
2. Fundamental Attribution Error (2) - We tend to look at our own accomplishments as evidence of our own ability, and our failures as events caused by external influence. When it comes to others it's the reverse, we look at others accomplishments as the result of external events, and their failures as evidence of their internal lacking of ability
How this applies: Let's face it, if you're working as a software developer, you don't always have the time to write 100% perfect code (which is not an excuse to write bad code) but a reason why we often settle for "good enough" code. We probably accept this rationalization when reading our own code but are less lenient when reading others code. This then frames their judgment of the code in a negative light. "I hate this code because the developer took shortcuts/didn't do things the right way... " Even though we do the same.
3. Mere Exposure Effect (3) - We like things we're familiar with.
How it applies: Since we wrote our code, know how it works (most of the time right...) and what we were thinking when we wrote it, that familiarity is pleasurable vs code that we don't know how it works (yet), and have less of an idea of the mindset that the developer had when writing it.
Those are just a few... there are probably more theories you can apply to this problem but I do agree it's a real thing.
So many times I've found myself jumping back and forth between new languages, trying to learn what might be the best for X field in 20XX.... Usually ending up learning very little.
Should you learn Swift? Possibly. But I'd be careful with learning for external motivators like job prospects.
I've found personal interest and wanting to build something as being the strongest motivators of learning
Productivity posters might spark motivation for a a short moment, but after that motivation leaves, you're back to relying on your regular patterns / habits
On a small team, most of our productivity comes in the morning after we've said hello and settled in. Gets real quiet and we all just get in the zone. As the day winds down we loosen up. It's a very pleasurable way of working, for us at least.
When it comes to "foo bar" examples, as a learner, I think it causes MORE cognitive load not less.
I think this is because, it's hard to make connections between meaningless words like foo, bar and baz
Conversely, most of the "aha" moments come from your ELI5-like explanations of concepts
The concept of a "promise" made sense to me when you used buying a hamburger at a fast food store in your workshop on asynchronous javascript.