That's the dumbest thing I've ever heard. You sound like a really inexperienced engineer, let alone CTO, that has never seen technology trends come and go, and sometimes you bet on the wrong horse.
I'd rather hire an junior React developer than someone with such hubris.
This seems like an outrageous statement on its face. They probably have React on their resume because that is where the job market has drifted. No one is getting hired these days, even at old-school Fortune 500 type companies, for listing "Java-Server-Pages" or "Jinja SSR templates" on their resume for a frontend position.
That was my initial reaction too. Then I realized that every web UI re-write I've seen was lead by developer evangelism, never by management. Developers update their resumes and HR updates hiring reqs accordingly.
This makes it harder to see this as something other than a developer-inflicted problem but for the fact that there are probably three groups of developers affected by this:
a) true-believer evangelists
b) resume-builders
c) innocent bystanders
There's no way to tell from the presence of "Framework X" on a resume where the developer falls between bystander and evangelist. Probably the CTO's point is that they do not like "Framework X", and cases of c) lack judgement and decisiveness for putting up with it?!
Anyway, funny to think about, especially in comparison to the playbook for changing the back-end frameworks.
You need some oversight on your candidate evaluation practices, for the sake of that organization.
Very few of your frontend candidates will be privileged enough to optimize for what you think is relevant. They exchange time for money, you know? Or do you know that.