What gives you the impression that people contributing to JS frameworks have the potential to meaningfully contribute to "hard problems" in molecular biology ?
On the macro level, the new generations of smart talented folks are choosing CS over other career choices.
Umm... he is arguing that CS is exactly what people should be focusing because CS (ML/data processing, etc.) applied to existing fields and data could lead to new insights - so more smart people going to CS is a good thing (at least according to Yegge).
My point is that CS has practically nothing to do with writing JS frameworks and frankly I doubt that most people doing JS development are the kind of people that could make significant contributions to CS or mentioned sciences - maybe a fraction of the top % - but JS is a low barrier to entry, easy to get simple things done, sufficient to solve real world problems like automating CRUD TPS reports - because someone needs to do that as well. I've had the misfortune of working with that platform - JS is by far the lowest quality ecosystem I've seen* (I never really got into PHP so I can't compare).
IMO Yegge makes a stronger point suggesting that data science people are being driven to "catbook" projects instead of "important stuff" - but those people are not your everyday JS developers.