Earlier quoted context omitted.
It is hard to imagine a tool less suited to working with multi-gigabyte data sets than JavaScript.
Yeah I'm really confused why working with 4GB+ datasets in the browser is a current need. Why does everything end up in web browsers these days? Is it only because developers aren't familiar with anything else?
It's because deployment is a harder problem than development (at least, it's harder for developers, because deployment is a social problem). The web is a pretty poor development target (though it keeps getting better), but it's a damn terrific deployment medium, and that's a winning tradeoff.