To summarize your point (and correct me if I'm mistaken), Apache httpd is legacy that people don't seem to want to make the effort to move off of, but still want the benefits of nginx, so they'll stand up nginx in front of httpd, rather than migrate off of Apache (and update their platforms to support that).

I feel the "marketing" concept is less actual marketing and more feature appeal, but I guess that's similar? Maybe not, though. Features provide actual value, whereas marketing is ... tricksy.