I think a big part of it is cultural. Java is a great language with tons of supporting frameworks, build systems, etc. But it's mostly geared towards larger ent

I think a big part of it is cultural. Java is a great language with tons of supporting frameworks, build systems, etc. But it's mostly geared towards larger enterprise companies. For a startup that is trying to be quick and nimble to get started, it doesn't attract the right type of talent or workflows. It can definitely be used for a startup and some do, but the hacker-y startup devs tends to lean towards other solutions.