IMHO UEFI is one of the dumbest things in a long history of dumb "innovations" in computer history. It adds complexity to a process which should be very simple and stripped down to the most basic needs: Booting a OS.
It's the implementation of UEFI/EFI/TianoCore that I find most problematic, and not the idea of having a console operating system.
I work regularly with servers that provide most or all of what EFI does, and within the console, though these servers provide it with considerably less confusion and hassle.
Having an embedded console can be very handy to have a functional operating system available in the firmware. Whether this is troubleshooting the server, or the boot process, or baseline server configuration without having to fire up an operating system or a diagnostic.
What's not so handy (with EFI) is the complete grab-bag user interfaces, nor the confusing array of consoles that can exist (the Shell, the menus, the BMC, and increasingly often a management widget), nor limitations around the callbacks. And the byte-code engine concept that was intended to avoid having to implement console (and boot) drivers for each new widget never really got traction.
Simply having boot drivers available as callbacks for the operating system would have been very handy for folks writing or porting an OS. Debugging in the bootstrap environment stinks.
IMHO, EFI just isn't a well-designed user interface. It seems to be a scatter-shot collection of pieces that were duct-taped together into a technology demonstration. And I'm not entirely certain the folks that originally built EFI ever intended the manufacturers present it to the end-users to use it as the primary console, either.
I am actually of the opinion that UEFI isn't "complex" enough—the best BIOS I've ever used is OpenBoot, with the Forth interpreter. Simple in some ways but very very flexible, more than enough to blow your while leg off. And yet more pleasant to use than anything else.
Instead UEFI is a whole OS of its own.