[charrondev]

Pretty sure the primary reason people stayed stuck in IE for so long was that Microsoft shipped it by default until very, very recently (even in home editions of windows).

You can add on top of that the rebranding they went through. If they had just done what they did now, and shipped the old rendering engine inside the new one as some kind “legacy mode” that sites could request then everyone else could have moved forward years ago and not had to deal with a stagnant browser.