Meanwhile, everybody who actually tried to follow the launch was confused about why there were two, which ones did what, why there was no interoperability, why wasn't hangouts being replaced, "Mobile-first? More like mobile-only," and "Should we even bother? They're going to kill them both off in three years anyway."
It absolutely did hurt the adoption rate -- It would have gone much better if Google management had announced one communication platform and committed to making it their bet going forward.
They were hedging, and it was obvious. Nobody wants to pay switching costs to use a new thing if the creator isn't even confident in their new thing.