I am not open to your ahistorical take on Google Chat and XMPP.
Google didn't do anything wrong by using an open standard.
They didn't do anything wrong by building a good interface that people liked to use.
And they didn't do anything wrong by disconnecting from the network when the spam and harassment outweighed the benefit to their users.
We, the XMPP community, failed to capitalize on success by diversifying the network. It's our own fault not enough nodes were there.
I say it all the time: decentralization is strength.