But the average vim user is jumping to new instances often, so if he has to reconfigure it everywhere he might as well install a different editor with a config.
I have over 100 custom keybindings in my Vim config and can assure you I can still use the default configuration without any issues, it's just a bit slower.
The few settings I find really important can just be quickly set with a couple commands. No big deal.
I am not sure thats true. vim does give you extra utility in its availability on a wide variety of server-type platforms, but I suspect most vim users are using it actively for development on their local (or docker etc) boxes