On the other hand, if you do web development work professionally (and I appreciate that you personally might not), you should seriously consider running at least the beta versions of browsers on a day-to-day basis, and consider testing in something even newer. If you don't, it's much more likely that a browser change/bug will regress your site for tens or hundreds of millions of users.

Again, I appreciate what you're saying, and it seems a reasonable request. However, I think it's unrealistic for a lot of developers.

For example, I work on multiple web-based projects in various capacities. Right now, just to test changes on one of my sites before releasing them, I run manual tests on about half a dozen desktop browsers and several mobile devices. (Automated testing is great, but there is only so far you can get with scripting, particularly when it comes to things like rendering glitches and responsiveness.)

If I put a change live on one of my sites, or worse, hand it over to a client or ship a web app embedded in network-enabled hardware, I shouldn't have to be constantly checking for blatant regressions in basic functionality every few weeks. In fact, I didn't have to, until the teams behind various popular browsers and plug-ins decided that the kind of major/minor/point releases the entire industry had been using successfully for decades weren't sufficient and pushing out whatever was ready at an arbitrary six-weekly interval was a better idea.

As for the rapid release cycle, my feeling is that process dramatically decreases the bug count. It forces everyone to keep the code in a roughly shippable condition all the time, and provides early feedback if a problem is introduced.

That's an admirable intent, but it clearly doesn't always work in practice. For a vast and complicated piece of software like a modern web browser, slipping in an occasional regression in a corner case is all but inevitable, but there have been your-browser-doesn't-work-at-all scale howlers that have been pushed out sometimes too.

I suspect what this really exposes is an over-reliance on automated tests and a false sense of security if all of the tests pass. With development at this kind of pace, and with the distributed and partly volunteer-led development model for these browsers, perhaps there just isn't time for more comprehensive reviews and high-level planning/architectural work and so on, but there is a reason those things have value.

As for decreasing the bug count, I fear that what is actually happening is that there are so many now and the target moves so fast that many of us have just given up on reporting them. Certainly for our project bug trackers here, Chrome used to be worse by a factor of several for browser bug issues, but Firefox spiked after going to rapid releases and has held the dubious honour of being the worst major browser for quality more often than not since that time. Several of these projects use modern but mainstream features from HTML5 and CSS3, but I'm not talking about bleeding edge or obscure features here.

It is, however, unequivocally false that no one cares about the quality of browsers or that all the focus is on features.

Please notice that I was very careful not to claim that. I do, however, feel that as a matter of priorities, quality of implementation often takes a back seat to ticking feature boxes and to performance at the moment.

Again, this is based directly off our own bug trackers. I could have described canvas and SVG issues not far from the kind of things simonsarris mentioned earlier in this thread, for example, and others in CSS3 backgrounds and borders, CSS3 animation, HTML5 media elements, and so on. In contrast, while the pace of development for IE is slower, it has far fewer blunder-type issues in basic functionality these days, in our (obviously anecdotal) experience.

As a final comment, I'm interested in these W3C tests you've mentioned a couple of times. I had no knowledge of anything like that before this thread. If you can share some sort of authoritative/definitive link to how that works, I'd appreciate that, as it sounds like I should learn about it.