I'm speculating, but if I was a gambling man I'd bet it has something to do with the immediate update from IE8 to IE11 in one fell swoop whereas most PCs would have gone through all the IE versions updating gradually since 2009.
I'm running two machines with Win7 x64 (Ultimate):
The first one is running for years and had no issues at all with this update.
The second one is brand new, has been installed one week ago and ran into this issue
(Installed from DVD, then installed SP1, then all available critical updates, about 150)
... so I think you theory might be valid ;)