[WorldMaker]

"This website is running long running scripts", "This website is not responding": those are already equivalents to the smoker warning that show up from time to time.

But what is any user supposed to do with a blinkenlight telling them what they already mostly know: that a website is bloated/slow/eating their machine slowly? If there was an alternative website, maybe they'd already be using it. If they thought complaining to the site's owners about it, maybe they already had or are already aware that they'd be shouting into a careless corporate void. That mostly just leaves uselessly blaming their browser for a blinkenlight that tells them something they already know and can't care about.