"JavaSciript" implies it's some scripting language related to Java, which was originally an idea, where it was meant to control Java Applets. But that is not a thing anymore. Thus the name makes no sense. "JS" is just a name only conflicting with my initials.
The name was exclusively chosen based on marketing considerations, to have it benefit from the Java hype of the time. It was actually called LiveScript before.
but "JS" implies it is some sort of amalgam of the J and S programming languages - or it doesn't and probably the Java implication doesn't exist anymore either - who really, on hearing the name in a modern context is going to think "hey, it must be a scripting version of that one really old programming language granddad in the office is always reminiscing about"?
sure they use it, but I sort of feel the groups that use it and JavaScript are no longer likely to cross over each other, and thus new devs will not be making the historical mistake of rhetorical misunderstanding that was made in the old days.
It works well as a modifier, and makes it easy to search for projects that are named after other common concepts or objects. It's also easy and natural- sounding to say for English speakers. Compared to other modifiers, it's more like "-dot-com" than "-lang", or even worse "libre-".
It’s smaller. The logo already just says JS. It doesn’t boost Java’s reputation. And people in the ecosystem don’t have to worry about oracle threatening them.