Why is the Node ecosystem like this? Why do people continue to choose it for popular projects vs. anything else?
It's the opposite of NIH syndrome. Need to left pad a string? Just import a library from some rando on the internet!
Primarily because of the original sin of JS being an awfully designed language. Partially because it's the most popular.
Because, like it or not, it does Write Once, Use Anywhere better than Java ever did.
It is pretty much the lowest common denominator for code.
Because it's written by a type of dev that thinks everything should use JS because that's what they used for 6 months while working at a FAANG company before getting laid off and since they worked at a FAANG company clearly they know better than you so if you attack them for using an extremely poor language you just aren't a seriously person so please shut up while I go fishing for some VC funds.
It's like asking why Claude Code is written with react, because the devs getting paid >$500k a year clearly know better d'uh.
Because it's written in Javascript and there are classes of highly-situational and not-especially-meaningful vulnerabilities that broadly impact the entire ecosystem ("prototype pollution" is the canonical example) that get counted individually in every occurrence in every NPM package.
It's not a real number, and, worse, it obscures the real figure of merit (/demerit). The Node ecosystem does have a real problem with its culture of sprawling dependencies. But it's not the first-order issue with this "1400" number.