I use Vim for regular development and has mapped <Space> to colon in normal mode, so for me it feels very much like a single action to just tap those three keys in quick succession with different fingers on one hand then tapping <Enter> with the other hand. It's like executing a fighting-game combo, the muscle memory makes it feel like a single action even though you're hitting several keys.

But it's arguably true that Vim is the wrong choice as the default commit editor since the majority of users probably will not feel very comfortable in that environment. In hindsight, nano would probably have been the better choice for default.

However, since I'm already a heavy Vim user (and have the vim-fugitive plugin installed), I would never go for anything else.