There's definitely no point to avoid them for IE. The point as I see it is that it should be avoided for every browser.

Indeed IE's users are having terrible experience anyway, but let's just don't push FF and Chrome to their memory limits, just because we don't care with our code.

One of the best parts when I develop client-side web-apps is the debugging and looking close what the garbage collector is doing. For example : I usually don't use `delete` keyword, since I know it might create a node that GC's can't clear.