Unfortunately, that's out of many corporate user's control. Many corporations have critical applications that haven't been maintained to current HTML specifications. In many cases, there just wasn't budget to do so. One of my previous projects was to upgrade a major automotive manufacturer from IE 6 to IE8, even though IE10 was just being released at the time. Yes, they were still on XP at the time too!
Having maintained a web site for ten years that supported millions of users, I was always surpised by the stats on OS and BROWSER types used. At least for the site I managed, it showed that users tended not to upgrade. They ran forever what was on the computer when it was purchased. The bane of web developers. Do they stay within the installed base, or do they incorporate new technology that may cause users some grief? There is no good answer to that question. What ever decision is reached, there will be a percentage of folks that have a different opinion.
bob