> "polyfill" that reverted the change that site owners could use as a stop-gap until they could properly update their apps to work correctly
then the site owners would just use the polyfill indefinitely, since it now works again. THe more expensive option of rewriting to conform is not going to give return on investment.
This is why breaking a bad thing is needed - the suffering has to happen. It's like getting the flu - to get better one must get sick first if you've been infected.
Possibly, but if they are that useful to users, those sites either need to be maintained or forked. Your argument could have just as easily been used to argue for Adobe Flash support(OK it's still sort of around, but it's nearly irrelevant at this point).
I am not going to go so far as to say breaking backward compatibility is never the right way to go, but "those sites either need to be maintained or forked" is not what is likely to happen; rather instead they'll just say "you have to use such-and-such a browser at such-and-such a version" and lock it in that way for a long time. Consider how big a business it was (is?) to have VMs specifically to keep running Web apps in IE6.
Maintained by who, forked by who? You can't just fork someone's work, there is copyright. Also any saved copy of website(think web archive) will stop working.
then the site owners would just use the polyfill indefinitely, since it now works again. THe more expensive option of rewriting to conform is not going to give return on investment.
This is why breaking a bad thing is needed - the suffering has to happen. It's like getting the flu - to get better one must get sick first if you've been infected.