Would you block any analytics tracker - even one that didn't share data with 3rd parties? (i.e. a tracker that was purely to enable to site owners to gain insight into their visitors)
Me too. If I'm visiting a website, I don't mind the operator of the site knowing about my visit or getting some basic stats about usage. It's when they compare notes to make a larger map of my visits across the web that I start getting nervous. And when they use that data to target advertising to me, I start blocking them.