Crawlers load images from <noscript> tags? Some might. As googlebot runs Javascript, would an image inside <noscript> be indexed into google image search?
While that's an interesting question, one of my points was about this common type of claim:
> guess
You admit you don't actually know. I don't either, which is why I program defensively and test for any feature I want to use.
A lot of people seem to be projecting what they want to see, reinforced by confirmation bias. Choosing Javascript based analytics is a great way to conclude that almost nobody uses Javascript.
These are some very popular plugins, so my thinking is maybe the answer lies somewhere in between, where security-conscious users are white listing sites they want to run scripts on. Not that they're running completely in js disabled mode. Even though it's a subtle difference I think it's relevant to the strategy one goes in with regarding noscript tag.
So this would make sense to me. If that's right, that most noscript users are just running these plugins, then those folks know that they're going to miss out with some sites, or they'll selectively enable javascript on a case-by-case basis.
This would probably require more extensive review of logs, to see if the person who originally downloaded the noscript image eventually came back to the site with javascript enabled. The likelihood is this would only happen if the site was not functional when they visited with javascript disabled.
EDIT: Looks like they covered this in comments. Even that doesn't convince me for some reason.