Basically the sequence of events as claimed by the author is that:
- XMPP, niche, small circles
- Google launches Talk that was XMPP compatible
- Millions joined Talk that could coop XMPP in theory
- The coop worked only sparingly and was unidirectional, i.e. Talk to XMPP ✅ but XMPP to Talk ❌
- Talk sucked up existing XMPP users as it was obviously a better option (bandwagon effect + unidirectional "compatibility" with XMPP)
- Talk defederated
This demonstrated exactly the importance of reciprocity. If they play dirty, kick them out asap.