Why do you believe capturing semantic events (update statements, delete statements, alter statements, etc...) is superior to capturing a log of the data changes?

Whilst there is an element of compactness when it comes to capturing semantic events, the benefit of using a simpler mechanism like logs means that you don't need to use a full database engine to parse the data, and may end up offering better performance (for example, no need to calculate what a commit rollback entails on every node, just do it on the master node and let the other nodes read the logs to know what to update).