I still use Apache because I trust it; and because the ease with which I can configure a Python server (i.e. mod_wsgi), a Ruby server (passenger) and a Perl server, while being able to make use of the same modules I've been using for years.
Also, a properly configured Varnish placed in front of Apache ruins Nginx at almost anything at scale. I've seen it.
Most web traffic is not long-lived, though.
But most web traffic is blocking. Going NIO requires caching - which is a huge penalty and a PITA; and doing it while not having actual users doesn't make sense.
Varnish isn't a webserver. You can put Varnish in front of nginx as well. :)
Agreed on the blocking.
On large sites, I've been doing a single HAProxy instance -> nginx instance on each webserver -> Unicorn app server on each webserver with really good results.
Also, a properly configured Varnish placed in front of Apache ruins Nginx at almost anything at scale. I've seen it.
But most web traffic is blocking. Going NIO requires caching - which is a huge penalty and a PITA; and doing it while not having actual users doesn't make sense.