The fuss is about Google embracing/extending and then suffocating every WWW technology they can't shove at least 20 ads into.
I mean... when something is widely displayed in the middle of a list of things that includes
* Gmail
* Google Docs
* Google Calendar
* Google Photos
* Google Search
and nothing else, then I would naively consider it to be roughly as "core" as the other things on the list. You wouldn't? Why not?