Never used it either. It sucked However 99% of all "RSS apps" for mobile phones, including the few that are worth anyone's time, use it for infrastructure.
I never used Google Reader. However, I do use an RSS reader. And to keep in sync across the devices, my reader uses Google Reader infrastructure---as do most readers. That is, I keep my reading history "in the cloud", this being one of the things the cloud is good at.
So, Google did the RSS sync thing well, so well that everyone else used the infrastructure. Google Reader itself though was, at best, meh. Everyone else used the Google Reader infrastructure invisibly, so there was no contribution to Google's coffers.
Google could have competed with a better RSS client, but they didn't. Instead, they have killed their poor client and also their pretty good infrastructure. As far as I can tell, that's the reason people are upset. They don't care about Google Reader, but the loss of the syncing infrastructure is a problem.