> Anybody can open up a browser and immediately start playing around with Javascript.
Tell me, if you were looking to teach people to write Java code for web applications (I know, perish the thought!), would you start them off writing applets?
> You simply can't say the same for Java, C, C++, or assembly--frameworks and the other nonsense notwithstanding.
Your statement about the ubiquity of JavaScript runtimes is really JavaScript's strongest feature IMHO, but I don't think it is terribly compelling in terms of developer accessibility. You could make something like that argument could say something pretty similar in support of DOS shell, PowerShell, AppleScript, VBScript, VSMacros, XSL, but no one would ever think that a defensible argument for them. Sure you want accessibility, but I think it's okay to suggest that a one click install not be outside the grasp or patience of a developer on their way to writing for distributed device systems... ;-) The difference between "open your browser and now start to learn this language" and "open your browser to download and install this app so you can start learning this language" shouldn't separate anyone who was going to make it in the first place.
You simply can't say the same for Java, C, C++, or assembly--frameworks and the other nonsense notwithstanding.