MS doesn't need me to fight it's battles, but... I think the problem doesn't lie with IE, rather (ahem) somewhere else ;)
..but seriously now, IE has inbuilt backward-compatibility with old methods, and features a number of convenience properties etc. Its standards support could be described as "not what it could be", but it's not that bad. In our case, IE wasn't guilty of anything other than offering an alternative.
The problem comes when people (me included) learn the IE-only techniques first, without realising (or being informed) that they are proprietary.