Because it was done by the government, not just by Google. Yes, Google played a major role and yes, the tech companies do a lot of deeply concerning things on their own. But I was still taken aback that actual government software was installed on my phone without my knowledge or permission. It's a really bad precedent to set.

The fact that Google and the government worked hand in glove to do this doesn't make it less disturbing. Arguably it's more disturbing.