+Sergio Andrés Gómez del Real
What's been the problem with ff? Have you tried running nightly? My experience has been that it is as stable as their releases but with the advantage of being able to preview features months before they go mainline.
For instance, you can enable tab isolation through about:config since around December (if you use it makes sure to create a new profile because, most assuredly, your mileage will vary). You get the latest in es6 implementations, they've just begun enabling of SIMD via js and they've finally turned on ggc!
Once again about ffos, aside from creating a new platform that benefits everyone, by targeting a very constrained mobile environment they force themselves to make a very efficient browser. My guess is that they realize that gecko isn't up to the task (it's biggest weakness by far is terrible DOM performance), they're not sure how to fix it, so that's why the work on servo with Samsung.
This was a bit rambling, so I beg your pardon.
In brief I'd say that Mozilla recognizes, and hopes, that the browser becomes the new linux. The web certainly has passionate, and very bright, people behind it, who wish to see a democratization of platform, something you can never do with native apps.