Its not presented in a very clear way from the charts alone -- Here the goal was to reduce/optimize the amount of unnecessary 'work' done. There is an implied

Its not presented in a very clear way from the charts alone -- Here the goal was to reduce/optimize the amount of unnecessary 'work' done. There is an implied cost of handling more work where contention is the root cause of extra (unnecessary) work. We're basically saying "I'd rather have a little more latency vs handle X times higher load". One common real world situation where this comes into play are things like thundering herd scenarios. Rather than trying to cope with huge bursts of traffic, we want to spread the load out in time.