Do you feel safer on a four-engine plane than you do on a twin? Since losing an engine usually means diverting, you might be more likely to have your trip interrupted on a 4- than a 2-engine plane.
Check out the graph at the end of this article (there's also good information about ETOPS).
Here's a fun great-circle mapper that also shows non-ETOPS areas. For example, here is HNL-LON.