I think there's a few things here worth considering.
- They're not really interchangable. Javascript is the de-facto king of the internet despite never earning this title through its own merits. Unless you think your users are going to run java applets on your website and javascript for your high-speed high-throughput environment they don't compete for the same use case.
- I don't agree with the arbitary lines people draw 'programming' and 'scripting', usually it's just an epithet to throw at languages that aren't compiled to binary. Besides, Java is a bytecode language, so is Javascript. From the spectrum of binary compiled to interpreted, they're both around the same.
