I doubt it's just that. If those things were actually great, people would have embraced them like they did slack.
Consider Google+ also. They had plenty of reference points for that. It was just not very good.
Google tends to abandon development on new projects way too quickly, before they're ready for mass appeal. They probably expect it to explode like Gmail did. But I think they forget they lost a lot of promotors like us when they abandoned the don't be evil thing.
At the time I recommended Gmail to everyone, now I try to get people away from Google :)
Before Slack there was Flowdock (which was never as popular) and I'm pretty sure another I'm forgetting from back then. I used Slack as probably the best-known example.
"We couldn't figure out how to market it" was from an interview straight from the people who made it: The companies they pitched to responded with things like "why would we need this, we have email".
Consider Google+ also. They had plenty of reference points for that. It was just not very good.
Google tends to abandon development on new projects way too quickly, before they're ready for mass appeal. They probably expect it to explode like Gmail did. But I think they forget they lost a lot of promotors like us when they abandoned the don't be evil thing.
At the time I recommended Gmail to everyone, now I try to get people away from Google :)