If any language had the tooling and development Java did it would hold the market share. It's my opinion that if Rust makes a similar IDE experience (even just using Eclipse's platform) with every feature like code completion, formatting, debugging, the hole 9 yards and integrate Cargo into it they'll win. But, here's the caveat: It needs to be FLAWLESS integration.
I've been a java developer for my entire programming career. Java was my first language when I was 12 and I'm 19 now. I still can't use javac without looking at a compiler guide since I never use it. Eclipse does the business and I don't ever even need to think about what's going on outside my code. Not once.