Loadable modules in nginx?

I am newbie to nginx and I read that in order to write custom modules,
they need to be recompiled with nginx. I expect this to be a bit of a
maintanence issue and wonder why we don’t have loadable modules. It
should not be hard to write some dlopen based code than can load a
dynamic set of modules at startup time. Is there any reason why this
won’t work (before I get started on writing such a “meta” module)