As a Verizon Galaxy Nexus owner who runs Cyanogenmod, I wasn’t terribly pleased either, but apparently it’s not all that arbitrary. The support ended three months before it was scheduled to. Let’s all let that soak in a bit.
And let’s get real here: the Cyanogenmod installer, from what I’ve seen about it, basically just enables ADB and instructs the user on how to plug the phone into a PC and run the Windows installer. It’s…not that big of a deal.