Wait what? So you should hire coders who don't like coding to do coding?
They often ignore the actual business problem that needs to be solved, because it can be solved using "boring" technology.
The reality is that people who like coding and thus trying new things are limited by the stack their job uses. Simple as that.
I don't really understand your hypothetical scenario where this alleged person is working on the new FooQux framework instead of getting work done. That's just someone who isn't doing their job. That they enjoying writing code seems irrelevant. Like trying to say people who like water skiing are awful employees because they're on the lake all day.
We need a word for this kind of HN trope. Condescension roleplaying?
That's the culture clash people frequently reference, and it's very real. If you don't perceive it, it's because you're swimming in it.
And I emphasize that the attitude, that the only good coders have tunnel vision and just want to play obsessively with tech, but only the cool stuff, goes far, far beyond the stereotypical SF startup environment or whatever. Because a large number of companies have a vague idea that to be cool, they should imitate what the trendy companies do, so even if you question the stereotype, the stereotype influences reality.
And the code isn't even "pretty" - it's just well-tested and is working as intended.
Makes one question some assumptions about what makes a good developer.