They did themselves over by tying IE so heavily in with windows explorer back in the IE4/IE5 days. It basically meant that upgrading IE was a hefty and error-prone process so people just didn't bother... and possibly switched to competitors. I remember trying to upgrade to IE5 on Win98 and it took down my windows installation.
And it looks like the same problem may still persist though to a lesser extent.
A WinXP SP3/IE7 user had a windows update popup the other day advising them to download and install IE8, so we clicked the link and followed the update process. After about 10 minutes of mysterious progress bar, I was informed that IE8 was not available on that platform. That user is now happily using Firefox.
As a developer, this was a nightmare. It's basically meant there was a huge persistent userbase of IE4-IE6, making it very difficult to use current web standards without horrible hacks.
The article author is correct, I found myself in web dev standstill from 2002-2006, having to develop for the lowest common denominator which was actually used by 95% of our site visitors!
But now with proliferation of other browsers that support the specs, it now gives me the confidence to use bits of CSS3, webfonts and HTML5 elements knowing that support will be increasingly available.
And hopefully with browsers generally implementing some sort of auto-update, more people will keep browsers up-to-date, so standards proliferation can happen faster. Developers will be able to use new specifications, faster. Imagine the W3C releasing some HTML5.1 standards and them being supported in browsers within 12 months... great!