I think a lot of people conflate criticism of JS with criticism of the way it's been used for the past number of years, putting a nuanced topic into a black-and-white "for or against" sort of discussion. I've done a number of projects heavily using JS-- vanilla, with modern frameworks, server-side and in the browser-- and aside from some fundamental annoyances with it's approach to a few things, it's been a great tool. There's nothing fundamental about JS itself that makes applications vulnerable to this like a buffer overflow would, but the way it is used right now seems to make it a lot easier for inexperienced, under-resourced, or even just distracted developers to open up big holes using generally accepted techniques.
But I've never been a full-time front-end-web or node dev, so maybe I'm mistaken? Compared to the server-side stuff I've worked with, there's definitely a concerning wild west vibe moving into modern JS environments. I think there was a casual "well, it's all in client-side userspace" attitude about the way it was used before which effectively shifted most of the security concerns to the browser. We should probably push a little harder to shake that. Think about how much JS your bank uses in their website? I'll bet they didn't write all of their own interaction libraries.