The QuakeLive team currently only has a single developer and it seems that they would have nowhere near the developer bandwidth to do a WebGL port (as great as a WebGL QuakeLive would be!)
As a long-time fan of the Doom&Quake games I would personally want to volunteer to help out on the JS porting aspect (I work on Emscripten, the compiler used in the Unreal Engine port and others).
However, how feasible this would be would depend on how portable the codebase is and so forth, which is not publicly known.
The UI for example is mostly new, I am not sure about rendering, asset management etc.
Sound and networking are certainly possible. Sound will use HTML audio or Web Audio, if the C codebases uses SDL audio (there is audio in the citadel demo). And networking is possible with not much effort, see for example https://developer.mozilla.org/en-US/demos/detail/bananabread
But I fully agree that a week for a tech demo is a small part of the work that a full product needs. Still, that it was just a week seems to say that a full product is feasible, probably months of work. Perhaps id doesn't want to spend that amount of time, and that's understandable if they have other priorities.
I've just never released it due to assets. I wanted to finish cross-compiling quake3 QVM-based mods to JS in order to enable playing some of the popular mods (with their own assets), but that just never happened.
I really wish some permission could be granted to use the original quake3 demo assets - it'd be great to have such a demanding gaming project for browsers to work on improving.
If assets are the last thing missing for you to launch it, what would it take to resolve that (not using the official assets, but something else)? Perhaps I can help or we can find others that can.
Problem is, websockets are currently TCP only (TCP is unacceptable for a fast-paced real-time game). I guess there's WebRT but the support for that is not very widespread. Chrome and Firefox render webgl using vsync, which adds an unacceptable amount of mouse latency to mouse input. Chrome apparently won't render at 60hz+ even if your refresh rate is above it. I'm sure there's some additional latency between mouse events and updating the game too. It's a very compelling tech demo, but not something at the level that could be sold as a complete product yet.
About vsync etc., I am not an expert on those. But the game should be able to render at 60fps (equal or better to consoles), see the demo above and also Epic Citadel etc.. Any worse means there is a bug, and we should file an issue and try to get it fixed.
Disabling vsync in about:flags definitely works, although it's an ugly thing for end-users to have to do. I've benchmarked 100> FPS by quake3's timedemo command through this method, although I don't recall trying to play the game and determining if the frames are actually being painted at that rate.