This isn't made for "most peoples" web sites, it's designed specifically for web apps with large Javascript footprints. Of which there are quite a few - the site I work on has ~200kB-400kB of JS resources.
It is for sites with large JS code, very high volume, and frequent revisions. I wouldn't do this if my site only had 1k logged in users per day or if I changed the code once a month.
[Citation required]^H^H^H^H^H^H^H^H Do you have any data which supports the statement regarding average size of script?
I suspect that the sites which might consider deploying something like this have "most" of the Javascript code on the internet if you look at bytes transferred, rather than number of URLs.
My apologies. The original comment was quite throwaway, so I didn't want to present too much of a formal refutation. However, I have adjusted the text slightly.