Request latency is certainly a factor, especially with more requests happening per page, and more demanding desktop-experience applications on the web. But, none of the servers I mentioned are a significant contributor to latency when configured appropriately for the workload. Apache has competent concurrency options on modern systems (including libevent), as does nginx.

Certainly performance is nice. I'm not saying it isn't. But, the webserver is going to spend most of its time waiting on your application and your database. I'd like to see folks more focused on standards-compliant behavior, secure behavior, etc. That's not as easy as slapping up an ab benchmark, but it's more useful in helping me decide if a new server is appropriate for my needs, and it's helpful in moving the state of the art forward on fronts that are far more important than squeezing another bajillion requests out of hardware that can already serve a bajillion requests.

Another interesting angle is memory usage. Apache does require more memory than nginx or, presumably, H2O. It's not a huge difference, if Apache is configured as minimally as nginx is, by default, but it's notable on a very high concurrency system. In the "Internet of things", small embeddable web servers will be important. If H2O uses less memory than nginx, that'd be interesting (I think more interesting than performance). But, memory usage isn't really mentioned anywhere that I see...if a memory graph were beside the ab benchmarks, I probably wouldn't have even complained about the benchmarks being so prominent. It would have added a useful and maybe even predictive piece of data to the page.