I think it's also about changing expectations and environment. Big customers expect timely updates for the purposes of security, keeping third party integration

I think it's also about changing expectations and environment. Big customers expect timely updates for the purposes of security, keeping third party integrations working, and bugfixing. They also expect high uptime and prompt outage mitigation. That's really hard to square with on-premise offerings. Don't get me wrong, it's also hard, but providing on-premise software is less difficult than it used to be in absolute terms. The main things that changed are SaaS driving expectations up, and needing to upgrade faster.