[tommyallen]

Vim already allows you to use :shell. Neovim took it a step further with the added benefit that you can treat the output as buffer text. Just because you can't see the advantages this gives developers doesn't mean it was a waste of time.

[nilved]

:shell is completely different. That's vim stepping out of the way while you run a subprocess. Moreover, vim having it is not an argument for Neovim to have it. If vim really had a terminal emulator Neovim should have removed it.