Why is Apache2 and httpd a dependency?

Due to the fact that Apache2 is a dependency those of us running NGINX run into a problem. We can install NGINX and get phpPgAdmin up and running just fine. However, since Apache2 is a dependency I am continually told Apache2 isn't running when trying to install packages. I try to install a package and it says

configuring phppgadmin.... Apache2 isn't running.

There isn't anything wrong at all, NGINX and phppgadmoinare working, but because Apache2 is a dependency I am constantly given an error when trying to install software and it is very annoying.

Now obviously I can download the package, and modify it s Apache isn't a dependency and then install it.

But why is Apache even a dependency to begin with? Most users installing phppgadmin probably already have their web server running anyway. PhPgAdmin can be ran with either NGINX or Apache, so why make Apache a dependency? Will there ever be a version of this package that doesn't have Apache2 as a dependency?