I chatted about just this timeout issue with an engineer from a major CDN while he was at my house enjoying the dialup. Seems like simply a matter of resource management; slow connections do use more resources. Most CDN customers don't care or don't know that a few percent of the US population is getting their web browsing broken by timeouts, so there's no push back.
(NASA has their wacky ways around the issue for ISS residents, something like VNC to a ground-based browser IIRC.)
That's pretty smart of NASA; things like a caching HTTP proxy still wouldn't work in some cases, given that sites can expect your browser to make a given AJAX request within X ms of requesting the page.
I wonder if there's still a more "API level" way to handle things, though, rather than making your computer into a dumb frame buffer client with extremely low responsiveness to typing/scrolling.
Maybe they could run a headless browser on Earth, and use a protocol like the Chromecast does to synchronize its DOM state to a "browser proxy" in space—like a higher-level, domain-specific version of the X11 protocol. That'd still have latency for JavaScript-based webapp UI, though... maybe the JS could be split and its state synchronized so that the "server" handles timer triggers, while the "client" handles input events.
I remember astronaut Alex Gertz somewhere saying the VNC was also for security reasons. Keep in mind that most infrastructure on the ISS was installed in the middle 00s and that the Thinkpads were possible running Windows XP and IE 6 then.
I'm surprised they need anything. I get my home internet from a satellite in geosynchronous orbit and it works fine other than the latency. No human has got that far from Earth since Apollo in the 1970s, so my home internet has to be worse than anyone NASA cares give internet. (though I have no idea what bandwidth NASA has)
If they wanted to use a geosynchronous satellite from the ISS, it would be occluded by the earth half of the time and the other half of the time they'd have to track it with a satellite dish over the course of the 45 minutes (out of every 1.5 hours) they have access to it.
of course the same is true of ground stations... I'm not actually sure how they do it but they probably don't need as high-gain of an antenna to reach them.
The ISS gets connectivity via a small number of ground stations and mostly satellites. Their connectivity is not uninterrupted; there are small regular time intervals at which none of their uplinks is in line of sight.
(NASA has their wacky ways around the issue for ISS residents, something like VNC to a ground-based browser IIRC.)