Earlier quoted context omitted.
You can, sure. 2 problems: 1) It will undoubtedly be slower than the current JS-quirks optimized VMs. 2) There is a shit-ton of JS on the web that has been tested to work with the current crop of VMs, moving to a new VM almost guarantees breakage. It's the same reason why GNU Screen isn't rewritten despite (supposedly) being a mess.
You're not the first person to posit that adding a new VM "almost guarantees breakage". So what? Keep the old VM, transition to the new one by specifying that's what you're targeting, then deprecate the old VM and eventually lose it altogether. You make it sound like the computing world has never introduced a new version of a language that has implications for the older ones and managed to overcome it. Even the web d…
And even then, you still have to support JavaScript being written directly in HTML tags, something no other language could enjoy. So every browser must include a JavaScript to (new VM) bytecode compiler. JavaScript will always be in a priviledged position.