From what I can tell most people responding are "single blog" people.

But the problems of the WP core back-end are manifest when you run a theme.. such as a Directory, Classifieds, Real Estate, Vacation Rentals, etc.

Where Users are permitted to self-register and to control their own posts -- ads, rentals, for sale properties, etc.

All of these commercial themes switched several years ago to customized Front End forms for creating and modifying posts. The User is redirected away from the "ugly" WP Dashboard in the WP Admin path. The User interface now exists inside custom forms and they never see the WP back end.

But, every single WP plugin must be administered in the core back end if it has User menus and sub-menus that alter the content of a post.

There is no way for a User (lesser roles than Admin) to utilize plugins that can only be seen in the WP core Admin dashboard.

I have a calendar plugin for Rental Bookings and Availability that offers the User (owner of posts) many options for creating and embedding their own calendars and reply forms into each post (rental type) they create. Unfortunately, my users have no access to these fine features because the plugin, as all WP plugins, can only be used in the WP backend. And the theme directs them away from the default backend.

Many new plugins can be written IF the back end options and settings can also show up in a custom front end.

If a plugin is installed that shows a menu and sub-menus to an Author role in the Wp Admin Dashboard then those tabs ought to be replicated in the User front end of any well built theme template. All back end functions that a plugin bestows upon a User ought to automatically be made available in a Front End menu, too.