Serious question. Please hit me with a clue stick. Regarding 1.9, how can "old-IE compatibility often causes problems of its own" and "simplest way to support older browsers is to use jQuery 1.x on your site, since it works for all browsers." both be true at one and the same time?
This is one of the biggest projects on the web leading the way in throwing shitty old IE under the bus to help push the modern web forward. They're going to keep big-fixing 1.X so people stuck with IE6/7/8 can keep supporting it, but moving forward with 2.x for modern browsers makes their lives easier in the long run, and provides yet another coffin nail in Microsoft's attempt decade-old attempt to break the web.
probably instead throwing the vendors that don't want to support old IE...