Killing Google Reader affected a relatively small number of users, but these users disporportionately happened to be founders, CTOs, VPs of engineering, social media luminaries, and people who eventually became founders, CTOs, etc. They had been painfully taught to not trust Google, and, since that time, they didn't. And still don't.
They had a core set of ultra-connected users who touched key aspects of the entire tech industry. The knowledge graph you could have built out of what those people read and shared…
They could have just kept the entire service running with, what, 2 software engineers? Such a waste.
The thing is: I guess they didnt see a good way to monetize it (according to their "metrics"), while the product itself had somehow relative high OpEx and being somehow a niche thingy.
like theoldreader and Inoreader, which explicitly copied the columnar interfaces, non-RSS bookmarklet content saving, item favoriting, friend-of-a-friend commenting and quasi-blog social sharing features, and mobile app sync options via APIs? Or NewsBlur, which did all of that _and also_ added user-configurable algorithmic filtering? Or Feedly, which copied Reader's UX but without the social features? or Tiny Tiny RSS and FreshRSS, which copied Reader's UX as self-hosted software?
theoldreader remains the most straightforward hosted ripoff of Google Reader, right down to look and feel, and hasn't changed much in more than a decade. Tiny Tiny is very similar, and similarly unchanging. FreshRSS implemented some non-RSS following features. So did NewsBlur, but as it always has, it still struggles with feed parsing and UI performance.
Inoreader and Feedly both pivoted toward business users and productivity to stay afloat, with the former's ditching of social features leading to another exodus of people who'd switched to it after Google Reader folded.
Picking up the pieces after Reader was impossible because the entire RSS ecosystem imploded with it. Almost every single news site decided that with killing Reader, they wouldn't bother maintaining their RSS feeds, leaving them basically all "legacy" until they irrevocably break one day and then get shut down for not wanting to get maintained.