> Their model is around workplace communication in general, it doesn't have to be remote
It doesn't, but I think the added value of Slack is much more prominent in remote scenario than when everybody is in (roughly) the same room. If it's not good enough to enable that - makes one think what it's good for?
> And maybe they're just pushers, not takers.
Then reasonable question to ask is - why not? What do they know that the takers don't?