> So, you have never had a JS application delivered over the web become unusable despite your attempts to only use it how and when you need to?

Of course I have, that’s not the point I was making. My point was that JS and the VMs it runs on are very fast, if you know how to use the language and when not to use it. That couldn’t possibly apply to apps you didn’t build. If I’d said C or whatever is fast if you know how to use it, I don’t think I’d get this comment about some horribly inefficient downloaded printer driver.