It's nice to see WebKit adopt this approach too. Chrome and Firefox have already had a policy against new CSS properties with vendor prefixes for over three years, so with Safari onboard too now it's becoming easier to imagine a future where web developers won't have to worry about writing code with prefixes anymore. The only potential reason to use them will be compatibility with older browser versions.
Technically, web developers should never had to have worried about writing code with prefixes - prefixed properties were never intended to be used for production apps. :)
Agreed, I would also say it's often not just the devs who build the requirements, hard to say something is impossible / not a good idea to implement when it's everywhere.
The problem is that "production" can have varying levels of tolerance to cutting edge features depending on who the audience is. Sometimes you know all your people are Chrome users, or IE10 users, or developers with the latest browsers, etc.
I was looking at our browser metrics the other day and it's yet to drop below the arbitrary 5% usage figure we use to fully deprecate browser support. We are a public facing site, and not particularly niche.
It's hovering around there, but if a user is still clinging to ie9 it's highly likely they don't have the ability or requirement to upgrade.
When ie9 legacy support drops my biggest headache will be ie10's squiffy flexbox support.
Having to support ie10 isn't the worst thing in the world. I was surprised when it was released because it was the first time I had ever marked up a page and it worked across all 4 browsers almost pixel perfect without any hacks or tweaks.
You should only really need to worry about IE10 if you have users on Windows Server 2012 baseline, whom should have likely already upgraded to R2 or more recent. Lifecycle support jumps to 11 on most OSes, yay!
The problem is not the tolerance to cutting edge, it's that the original point of prefixed properties was they were unstable and could be changed slightly or completely. Once you've shipped to production that's dead, there's no guarantee you'll update it.
