I find this specious: What modern web app isn't minifying/concatenating it's Javascript and CSS source? All of your concerns are easily remedied via a proper build procedure. And we're talking about, in relative terms, miniscule amounts of data for the web. 33 kb? C'mon now.
> I find this specious: What modern web app isn't minifying/concatenating it's Javascript and CSS source?
In that case, you should learn more about web performance: minification is a useful tool but it's not magic. If you add code to a bundle, you're almost certainly transferring too much data for the initial request — which increases the time before anything can run — and making caching less efficient because any change to your JavaScript invalidates the entire cached object; if you serve it separately, caching works better but you'll incur the latency cost multiple times. Every site has to balance these factors against user capabilities and the site performance targets.
To illustrate why you're being entirely too cavalier, consider Ilya Grigorik's excellent Velocity 2013 presentation detailing exactly what it takes to reliably deliver a rendered webpage in 1 second on mobile:
Note that his performance target is roughly 14KB transfer to deal with the way 3G performs in the real world. If you were thinking about including jQuery, you just blew that budget twice over: a fully compressed, gzipped copy of jQuery 2.0.2 is 29KB. If you concatenated everything, you not only blew your transfer budget but you ensured that none of your JavaScript, even the parts which are entirely self-contained, executes within that performance target.
The point isn't that CDNs aren't useful (they're great), asset packaging isn't good (it's a key tool), or even that jQuery is bloated, but rather that good engineers make decisions based on their performance goals and actual measured user performance rather than flippantly saying “We use a CDN so the site will be fast!” (contra: healthcare.gov) or “everything is minified, so it'll be fast”.
